U.S. patent application number 17/521243 was filed with the patent office on 2022-02-24 for brake systems integrated into vehicle corner modules and methods of use thereof.
The applicant listed for this patent is REE AUTOMOTIVE LTD.. Invention is credited to Shmuel CHIOCLEA, Neta DORON, Hanan ORLOV, Ahishay SARDES, Tomer SEGEV.
Application Number | 20220055586 17/521243 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-24 |
United States Patent
Application |
20220055586 |
Kind Code |
A1 |
ORLOV; Hanan ; et
al. |
February 24, 2022 |
BRAKE SYSTEMS INTEGRATED INTO VEHICLE CORNER MODULES AND METHODS OF
USE THEREOF
Abstract
A Vehicle Corner Module (VCM) based brake system, which includes
a brake actuator, adapted to regulate the rotation rate of the
wheel assembled to the VCM, a fluid-based brake power source,
fluidly connected to the brake actuator and adapted to provide
pressurized brake fluid for operating the brake actuator, and a
brake-control-circuit, functionally associated with the brake
actuator and with the brake power source, and adapted to provide
functional inputs to the brake actuator based on a target rotation
rate profile desired for a wheel mounted on the VCM. All mechanical
components of the VCM-based brake system are disposed within the
VCM. The VCM-based brake system and the vehicle platform are not in
fluid communication with each other.
Inventors: |
ORLOV; Hanan; (BET-GUVRIN,
IL) ; SARDES; Ahishay; (Tel Aviv, IL) ; SEGEV;
Tomer; (Tel Aviv, IL) ; DORON; Neta; (Tel
Aviv, IL) ; CHIOCLEA; Shmuel; (Tel Aviv, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
REE AUTOMOTIVE LTD. |
Herzliya |
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IL |
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Appl. No.: |
17/521243 |
Filed: |
November 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/IB2021/055635 |
Jun 24, 2021 |
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17521243 |
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63043150 |
Jun 24, 2020 |
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International
Class: |
B60T 8/40 20060101
B60T008/40; B60T 8/42 20060101 B60T008/42; B60T 13/68 20060101
B60T013/68 |
Claims
1. A Vehicle Corner Module (VCM) based brake system adapted to be
between a wheel assembled to a VCM connectable to a vehicle
platform, and the vehicle platform, the VCM-based brake system
comprising: (a) a brake actuator, adapted to regulate the rotation
rate of the wheel assembled to the VCM; (b) a fluid-based brake
power source, mechanically and fluidly connected to the brake
actuator and adapted to provide brake fluid for operating the brake
actuator; and (c) a brake-control-circuit, functionally associated
with the brake actuator and with the brake power source, and
adapted to provide functional inputs to the brake actuator based on
a target rotation rate profile desired for the wheel, wherein the
brake actuator, the brake power source, and the
brake-control-circuit are disposed within the VCM.
2. The VCM-based brake system of claim 1, further comprising a
brake-interface-circuit, adapted to facilitate communication
between the brake-control-circuit and at least one computing unit
external to the VCM.
3. The VCM-based brake system of claim 2, wherein the
brake-interface-circuit is adapted to facilitate communication
between the brake-control-circuit and a vehicle-control-circuit
mounted onto the vehicle platform.
4. The VCM-based brake system of claim 2, wherein the
brake-interface-circuit is adapted to facilitate communication
between the brake-control-circuit and another control-circuit,
external to the VCM.
5. The VCM-based brake system of claim 1, further comprising a
speed-control-circuit including: a storage circuit adapted to store
the target rotation rate profile desired for the wheel; a feedback
loop adapted to compare a measured rotation rate profile of the
wheel to the target rotation rate profile; and a communication
interface functionally associated with the brake-control-circuit,
adapted to provide the target rotation rate profile to the
brake-control-circuit.
6. The VCM-based brake system of claim 1, wherein the fluid-based
brake power source comprises: a brake fluid source storing the
brake fluid; and a fluid pump disposed downstream of the brake
fluid source in fluid communication with the brake fluid source and
with the brake actuator, the fluid pump adapted to regulate a fluid
pressure of the brake fluid delivered from the brake fluid source
to the brake actuator for actuation of the brake actuator.
7. The VCM-based brake system of claim 6, further comprising a
brake modulator including at least one valve, wherein in at least
one state of the valve, the valve is in fluid communication with
the brake actuator, the brake modulator adapted to regulate flow of
the brake fluid between the brake actuator, the brake fluid source,
and the fluid pump.
8. The VCM-based brake system of claim 7, wherein the at least one
valve comprises: a fluid inlet valve having at least one operative
orientation adapted to allow flow of pressurized brake fluid from
the fluid pump to the brake actuator; and a fluid release valve
having at least one operative orientation adapted to allow release
of brake fluid from the brake actuator toward the brake fluid
source.
9. The VCM-based brake system of claim 7, wherein the at least one
valve comprises a single valve having at least a fluid inlet
operative orientation and a fluid release operative orientation,
wherein in the fluid inlet operative orientation the single valve
is adapted to allow flow of pressurized brake fluid from the fluid
pump to the brake actuator, and in the fluid release operative
orientation the single valve is adapted to allow release of brake
fluid from the brake actuator toward the brake fluid source.
10. The VCM-based brake system of claim 7, wherein the brake
modulator includes a brake actuator pressure sensor, adapted to
sense a pressure applied by the brake actuator, and to provide
readings of the sensed brake actuator pressure to the
brake-control-circuit.
11. The VCM-based brake system of claim 7, wherein the brake
modulator includes an actuator fluid pressure sensor, adapted to
sense a pressure of fluid provided to the brake actuator, and to
provide readings of the sensed fluid pressure to the
brake-control-circuit.
12. The VCM-based brake system of claim 7, wherein the brake power
source functions as a pressure modulator, functionally associated
with the fluid pump and with the brake modulator, the pressure
modulator having a fluid accumulator disposed downstream of the
fluid pump, in fluid communication with the brake modulator, the
fluid pump being adapted to provide pressurized brake fluid to the
fluid accumulator for storage therein, and the fluid accumulator
being adapted to provide pressurized fluid to the brake for
actuation of the brake actuator.
13. The VCM-based brake system of claim 12, wherein the pressure
modulator is adapted to modulate pressure of brake fluid supplied
to the brake actuator.
14. The VCM-based brake system of claim 12, wherein the fluid pump
is adapted to provide brake fluid to the pressurized fluid
accumulator independently of the brake-control-circuit providing
the functional inputs to the brake actuator for actuation
thereof.
15. The VCM based brake system of claim 12, wherein the fluid pump
is adapted to generate fluid at a target pressure, for accumulation
within the fluid accumulator.
16. The VCM-based brake system of claim 12, further comprising a
no-return valve disposed on a fluid line connecting the pressure
modulator and the brake modulator, the no-return valve is adapted
to allow fluid flow only from the fluid accumulator to the brake
modulator, and not in the opposing direction.
17. The VCM-based brake system of claim 12, wherein the brake
control circuit is adapted to provide control inputs to the brake
modulator and to the pressure modulator.
18. The VCM-based brake system of claim 12, wherein the brake
modulator includes a modulator pressure sensor, adapted to sense a
pressure of fluid provided from the pressure modulator to the brake
modulator, and to provide readings of the sensed fluid pressure to
the brake-control-circuit.
19. The VCM-based brake system of claim 1, further comprising a
brake regeneration module disposed within the VCM, wherein the
brake-control-circuit is adapted to regulate activation of at least
one of the brake regeneration module and the brake actuator.
20. A vehicle corner module (VCM) for regulating motion of a
vehicle, comprising: a sub-frame including a wheel hub, adapted for
mounting of a wheel thereon, and a vehicle-connection interface for
connection of the sub-frame to a vehicle platform; a VCM-based
brake system according to claim 1, mounted onto the sub-frame
between the wheel hub and the connection interface; and a motor
adapted to rotate the wheel, wherein the brake-control-circuit is
configured to control a rotation rate of the wheel.
21. The VCM of claim 20, wherein a specific VCM is functionally
mountable onto the vehicle platforms of at least two different
vehicles, the at least two different vehicles being of two
different types or of two different models.
22. A vehicle, comprising: a vehicle platform, having at least one
Vehicle Corner Module (VCM)-connection interface for mechanical
connection to a VCM; at least one VCM of claim 20, the
vehicle-connection interface of the at least one VCM connected to
the at least one VCM-connection interface.
23. The vehicle of claim 22, wherein the VCM-based brake system is
a fluid operated VCM-based brake system, and the VCM-based brake
system and the vehicle platform are not in fluid communication with
each other.
24. The vehicle of claim 22, wherein: the vehicle platform includes
a first VCM-connection interface and a second VCM-connection
interface; the at least one VCM comprises a first VCM including a
first VCM-based brake system and a first vehicle-connection
interface connected to the first VCM-connection interface of the
vehicle platform, and a second VCM including a second VCM-based
brake system and a second vehicle-connection interface connected to
the second VCM-connection interface of the vehicle platform; the
first VCM-based brake system is of a first type, and the second
VCM-based brake system is of a second type, the second type being
different from the first type.
25. The VCM-based brake system of claim 1, wherein the VCM-based
brake system and the vehicle platform are not in fluid
communication with each other.
26. The VCM-based brake system of claim 1, wherein the VCM-based
system is airtight and fluid tight within the VCM.
27. The VCM-based brake system of claim 1, wherein the VCM-based
system is mechanically decoupled from the vehicle platform.
28. A Vehicle Corner Module (VCM) based brake system adapted to be
between a wheel assembled to a VCM connectable to a vehicle
platform, and the vehicle platform, the VCM-based brake system
comprising: (a) a brake actuator, adapted to regulate the rotation
rate of the wheel assembled to the VCM; (b) a brake power source,
mechanically connected to the brake actuator and adapted to provide
power for operating the brake actuator, the brake power source
comprising: a brake fluid source storing the brake fluid; and a
fluid pump disposed downstream of the brake fluid source in fluid
communication with the brake fluid source and with the brake
actuator; (c) a brake-control-circuit, functionally associated with
the brake actuator and with the brake power source, and adapted to
provide functional inputs to the brake actuator based on a target
rotation rate profile desired for the wheel; and (d) a brake
modulator in fluid communication with the brake actuator, the brake
modulator adapted to regulate flow of the brake fluid between the
brake actuator, the brake fluid source, and the fluid pump, wherein
the brake actuator, the brake power source, the
brake-control-circuit, and the brake modulator are disposed within
the VCM, and wherein the brake power source functions as a pressure
modulator, the pressure modulator having a fluid accumulator
disposed downstream of the fluid pump, in fluid communication with
the brake modulator, the fluid pump being adapted to provide
pressurized brake fluid to the fluid accumulator for storage
therein, and the fluid accumulator being adapted to provide
pressurized fluid to the brake for actuation of the brake
actuator.
29. The VCM based brake system of claim 28, wherein the fluid pump
is adapted to generate fluid at a target pressure, for accumulation
within the fluid accumulator.
30. A vehicle corner module (VCM) for regulating motion of a
vehicle, comprising: a sub-frame including a wheel hub, adapted for
mounting of a wheel thereon, and a vehicle-connection interface for
connection of the sub-frame to a vehicle platform; a VCM-based
brake system according to claim 28, mounted onto the sub-frame
between the wheel hub and the connection interface; and a motor
adapted to rotate the wheel, wherein the brake-control-circuit is
configured to control a rotation rate of the wheel.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of
PCT/IB2021/055635 filed on Jun. 24, 2021, which is incorporated
herein by reference in its entirety. PCT/IB2021/055635 claims the
benefit of U.S. Provisional Patent Application No. 63/043,150 filed
on Jun. 24, 2020, which is incorporated herein by reference in its
entirely.
FIELD OF THE INVENTION
[0002] The present invention relates to vehicle brake systems and
particularly to vehicle brake systems integrated in Vehicle Corner
Modules (VCMs), and to methods of operating and servicing such
brake systems.
BACKGROUND OF THE INVENTION
[0003] In recent years, autonomous and electric cars have been
developed. One of the technologies that assists in the development
of autonomous and electric cars is that of the
vehicle-corner-module (VCM), to which the wheels are typically
mounted, and as such VCMs are also known as
wheel-corner-modules.
[0004] Some modern vehicles include driver assisting systems, which
are typically associated with the brake system. Stability control
systems (also known as Electronic Stability Programs (ESP) or
Electronic Stability Control (ESC) systems), may also include one
or more other driver assisting assemblies, such as ABS (Anti-lock
brake), TCS (Traction control system), HAC (hill-start assist
control), and the like. ESC systems typically include a hydraulic
4-channel ESC modulator, having 12 valves. The ESC modulator
regulates fluid flow to/from all the brake actuators of the
vehicle, for example via pressure inlet/outlet valves, to operate
the brake actuators. It is common that the ESC modulator regulates
the operation of brake actuators for vehicle speed reduction (e.g.
by master cylinder, adaptive cruise control, auto emergency braking
(AEB)), as well as for braking actions resulting from a
computerized brake instruction (e.g. for stability control).
Typically, vehicles have a centralized ESC system, wherein
components of the system, including an ESC control circuit, the ESC
modulator, and a fluid pump, are all located on the vehicle
platform.
[0005] There is a need in the art for braking systems suitable for
VCMs in which servicing and installation of the brake system are
simple and safe.
SUMMARY
[0006] According to an aspect of some embodiments of the present
invention there is provided a Vehicle Corner Module (VCM) based
brake system adapted to be between a wheel assembled to a VCM
connectable to a vehicle platform, and the vehicle platform. The
VCM-based brake system includes a brake actuator, adapted to
regulate the rotation rate of the wheel assembled to the VCM. The
VCM-based brake system further includes a fluid-based brake power
source, fluidly connected to the brake actuator and adapted to
provide pressurized brake fluid for operating the brake actuator.
The VCM-based brake system also includes a brake-control-circuit,
functionally associated with the brake actuator and with the brake
power source, and adapted to provide functional inputs to the brake
actuator based on a target rotation rate profile desired for the
wheel. In some embodiments, all mechanical components of the
VCM-based brake system are disposed within the VCM, and the
VCM-based brake system and the vehicle platform are not in fluid
communication with each other.
[0007] In some embodiments, the VCM-based system is airtight and
fluid tight within the VCM. In some embodiments, the VCM-based
system is mechanically decoupled from the vehicle platform.
[0008] In some embodiments, the fluid-based brake power source is a
hydraulic brake power source.
[0009] According to another aspect of some embodiments of the
present invention there is provided a Vehicle Corner Module (VCM)
based brake system adapted to be between a wheel assembled to a VCM
connectable to a vehicle platform, and the vehicle platform. The
VCM-based brake system includes a brake actuator, adapted to
regulate the rotation rate of the wheel assembled to the VCM. The
VCM-based brake system further includes a fluid-based brake power
source, fluidly connected to the brake actuator and adapted to
provide pressurized brake fluid for operating the brake actuator.
The VCM-based brake system also includes a brake-control-circuit,
functionally associated with the brake actuator and with the brake
power source, and adapted to provide functional inputs to the brake
actuator based on a target rotation rate profile desired for the
wheel. In some embodiments, all mechanical components of the
VCM-based brake system are disposed within the VCM and the
VCM-based brake system is air-tight, and fluid-tight, within the
VCM.
[0010] In some embodiments, the fluid-based brake power source is a
hydraulic brake power source. In some embodiments, the VCM-based
system is mechanically decoupled from the vehicle platform.
[0011] According to a further aspect of some embodiments of the
present invention there is provided a Vehicle Corner Module (VCM)
based brake system adapted to be between a wheel assembled to a VCM
connectable to a vehicle platform, and the vehicle platform. The
VCM-based brake system includes a brake actuator, adapted to
regulate the rotation rate of the wheel assembled to the VCM. The
VCM-based brake system further includes a fluid-based brake power
source, fluidly connected to the brake actuator and adapted to
provide pressurized brake fluid for operating the brake actuator.
The VCM-based brake system also includes a brake-control-circuit,
functionally associated with the brake actuator and with the brake
power source, and adapted to provide functional inputs to the brake
actuator based on a target rotation rate profile desired for the
wheel. In some embodiments, all mechanical components of the
VCM-based brake system are disposed within the VCM, and the
VCM-based brake system is mechanically decoupled from the vehicle
platform.
[0012] In some embodiments, the fluid-based brake power source is a
hydraulic brake power source.
[0013] According to yet another aspect of some embodiments of the
present invention there is provided a Vehicle Corner Module (VCM)
based brake system adapted to be between a wheel assembled to a VCM
connectable to a vehicle platform, and the vehicle platform. The
VCM-based brake system includes a brake actuator, adapted to
regulate the rotation rate of the wheel assembled to the VCM. The
VCM-based brake system further includes a brake power source,
fluidly connected to the brake actuator and adapted to provide
power for operating the brake actuator. The VCM-based brake system
also includes a brake-control-circuit, functionally associated with
the brake actuator and with the brake power source, and adapted to
provide functional inputs to the brake actuator based on a target
rotation rate profile desired for the wheel. The brake actuator,
the brake power source, and the brake-control-circuit are disposed
within the VCM.
[0014] In some embodiments, the brake power source is a fluid-based
brake power source fluidly connected to the brake actuator and
adapted to provide brake fluid for operating the brake
actuator.
[0015] In some embodiments, the VCM-based brake system further
includes a brake-interface-circuit, adapted to facilitate
communication between the brake-control-circuit and at least one
computing unit external to the VCM. In some embodiments, the
brake-interface-circuit is adapted to facilitate communication
between the brake-control-circuit and a vehicle-control-circuit
mounted onto the vehicle platform. In some other embodiments, the
brake-interface-circuit is adapted to facilitate communication
between the brake-control-circuit and another control-circuit,
external to the VCM.
[0016] In some embodiments, the VCM-based brake system further
includes a speed-control-circuit including a storage circuit
adapted to store the target rotation rate profile desired for the
wheel, a feedback loop adapted to compare a measured rotation rate
profile of the wheel to the target rotation rate profile, and a
communication interface functionally associated with the
brake-control-circuit, adapted to provide the target rotation rate
profile to the brake-control-circuit.
[0017] In some such embodiments, the VCM-based brake system further
includes a wheel rotation sensor functionally associated with the
feedback loop, the wheel rotation sensor adapted to provide to the
feedback loop inputs indicating the measured rotation rate of the
wheel.
[0018] In some embodiments, the brake power source includes a brake
fluid source storing the brake fluid and a fluid pump disposed
downstream of the fluid source in fluid communication with the
brake fluid source and with the brake actuator, the fluid pump
adapted to regulate a fluid pressure of the brake fluid delivered
from the brake fluid source to the brake actuator for actuation of
the brake actuator.
[0019] In some embodiments, the VCM-based brake system further
includes a brake modulator including at least one valve, wherein in
at least one state of the valve, the valve is in fluid
communication with the brake actuator, the brake modulator adapted
to regulate flow of the brake fluid between the brake actuator, the
brake fluid source, and the fluid pump. In some such embodiments,
the at least one valve includes a fluid inlet valve having at least
one operative orientation adapted to allow flow of pressurized
brake fluid from the fluid pump to the brake actuator, and a fluid
release valve having at least one operative orientation adapted to
allow release of brake fluid from the brake actuator toward the
brake fluid source. In some other embodiments, the at least one
valve includes a single valve having at least a fluid inlet
operative orientation and a fluid release operative orientation,
wherein in the fluid inlet operative orientation the single valve
is adapted to allow flow of pressurized brake fluid from the fluid
pump to the brake actuator, and in the fluid release operative
orientation the single valve is adapted to allow release of brake
fluid from the brake actuator toward the brake fluid source.
[0020] In some embodiments, the brake modulator is adapted to
receive control inputs from the brake-control-circuit of the VCM.
In some embodiments, the brake modulator includes a brake actuator
pressure sensor, adapted to sense a pressure applied by the brake
actuator, and to provide readings of the sensed brake actuator
pressure to the brake-control-circuit. In some embodiments, the
brake modulator includes an actuator fluid pressure sensor, adapted
to sense a pressure of fluid provided to the brake actuator, and to
provide readings of the sensed fluid pressure to the
brake-control-circuit.
[0021] In some embodiments, the brake modulator forms part of the
brake-control-circuit. In some other embodiments, the brake
modulator forms part of the brake actuator.
[0022] In some embodiments, the brake power source functions as a
pressure modulator, functionally associated with the fluid pump and
with the brake modulator, the pressure modulator having a
pressurized fluid accumulator disposed downstream of the fluid
pump, in fluid communication with the brake modulator, the fluid
pump being adapted to provide pressurized brake fluid to the
pressurized fluid accumulator for storage therein, and the
pressurized fluid accumulator being adapted to provide pressurized
fluid to the brake for actuation of the brake actuator.
[0023] In some embodiments, the pressure modulator is adapted to
modulate pressure of brake fluid supplied to the brake actuator. In
some embodiments, the fluid pump is adapted to provide pressurized
brake fluid to the pressurized fluid accumulator independently of
the brake-control-circuit providing the functional inputs to the
brake actuator for actuation thereof. In some embodiments, the
fluid pump is adapted to generate fluid at a target pressure, for
accumulation within the pressurized fluid accumulator.
[0024] In some embodiments, the VCM-based brake system further
includes a no-return valve disposed on a fluid line connecting the
pressure modulator and the brake modulator, the no-return valve is
adapted to allow fluid flow only from the pressurized fluid
accumulator to the brake modulator, and not in the opposing
direction.
[0025] In some embodiments, the brake control circuit is adapted to
provide control inputs to the brake modulator and to the pressure
modulator.
[0026] In some embodiments, the brake modulator includes a
modulator pressure sensor, adapted to sense a pressure of fluid
provided from the pressure modulator to the brake modulator, and to
provide readings of the sensed fluid pressure to the
brake-control-circuit.
[0027] In some embodiments, the VCM-based brake system further
includes a brake regeneration module disposed within the VCM, the
brake-control-circuit being adapted to regulate activation of at
least one of the brake regeneration module and the brake
actuator.
[0028] According to another aspect of some embodiments of the
present invention there is provided a vehicle corner module (VCM)
for regulating motion of a vehicle, including a sub-frame including
a wheel hub, adapted for mounting of a wheel thereon, and a
vehicle-connection interface for connection of the sub-frame to a
vehicle platform, a VCM-based brake system according to any one of
the embodiments herein, mounted onto the sub-frame between the
wheel hub and the connection interface, and a motor adapted to
rotate the wheel, where the brake-control-circuit is configured to
control a rotation rate of the wheel.
[0029] In some embodiments, a specific VCM is functionally
mountable onto the vehicle platforms of at least two different
vehicles, the at least two different vehicles being of two
different types or of two different models.
[0030] According to a further aspect of some embodiments of the
present invention there is provided a vehicle, including a vehicle
platform, having at least one Vehicle Corner Module
(VCM)-connection interface for mechanical connection to a VCM, and
at least one VCM as described herein, the vehicle-connection
interface of the at least one VCM connected to the at least one
VCM-connection interface.
[0031] In some embodiments, the VCM-based brake system is a fluid
operated VCM-based brake system, and there is no fluid
communication between the VCM-based brake system and the vehicle
platform.
[0032] In some embodiments, the vehicle platform includes a first
VCM-connection interface and a second VCM-connection interface and
the at least one VCM includes a first VCM including a first
VCM-based brake system and a first vehicle-connection interface
connected to the first VCM-connection interface of the vehicle
platform, and a second VCM including a second VCM-based brake
system and a second vehicle-connection interface connected to the
second VCM-connection interface of the vehicle platform. The first
VCM-based brake system is of a first type, and the second VCM-based
brake system is of a second type, the second type being different
from the first type. In some embodiments, the first VCM connection
interface is at a front portion of the vehicle platform, and the
second VCM connection interface is at the rear portion of the
vehicle platform. In some other embodiments, the first VCM
connection interface is on the right side of the vehicle platform,
and the second VCM connection interface is on the left side of the
vehicle platform.
[0033] In some embodiments, the at least one VCM includes two VCMs,
each of the two VCMs including a communication interface, adapted
for intercommunication between the two VCMs. In some embodiments,
the intercommunication between the two VCMs includes wireless
communication. In some embodiments, the intercommunication between
the two VCMs includes wired communication via a communication
channel mounted onto the vehicle platform. In some embodiments, the
intercommunication between the two VCMs takes place via a computing
device remote from the vehicle platform.
[0034] According to a further aspect of some embodiments of the
present invention there is provided a method of operating the
VCM-based brake system of aspects of the disclosed technology, the
method including:
[0035] at the brake-control-circuit, obtaining a measured wheel
rotation rate of the wheel;
[0036] at the brake-control-circuit, obtaining a target wheel
rotation rate for the wheel;
[0037] comparing the measured wheel rotation rate to the target
wheel rotation rate;
[0038] in response to identifying that the actual wheel rotation
rate is higher than the target wheel rotation rate, activating the
brake actuator; and
[0039] in response to identifying that the actual wheel rotation
rate is lower than the target wheel rotation rate, deactivating the
brake actuator.
[0040] According to another aspect of some embodiments of the
present invention there is provided a method of servicing the
VCM-based brake system of a vehicle including at least one VCM
according to aspects of the disclosed technology attached to a
vehicle platform, the method including detaching the VCM from the
vehicle platform, and while the VCM is detached from the vehicle
platform, servicing the VCM-based brake system accommodated within
the VCM.
[0041] In some embodiments, the method further includes, during the
servicing of the VCM-based brake system attaching a replacement VCM
including a replacement VCM-based brake system to the vehicle
platform, and operating the vehicle using the replacement VCM-based
brake system.
[0042] In some embodiments, the servicing of the VCM-based brake
system occurs at a location remote from the vehicle platform.
[0043] According to another aspect of some embodiments of the
present invention there is provided a method of operating a Vehicle
Corner Module (VCM)-based brake system including at least one
control circuit, the VCM-based brake system being disposed within a
VCM, the method including:
[0044] at the control circuit, obtaining a measured wheel rotation
rate of a wheel mounted onto the VCM;
[0045] at the control circuit, obtaining a target wheel rotation
rate for the wheel;
[0046] comparing the measured wheel rotation rate to the target
wheel rotation rate;
[0047] in response to identifying that the actual wheel rotation
rate is higher than the target wheel rotation rate, activating a
brake actuator of the VCM-based brake system; and
[0048] in response to identifying that the actual wheel rotation
rate is lower than the target wheel rotation rate, deactivating the
brake actuator of the VCM-based brake system.
[0049] In some embodiments, the VCM-based brake system is
functionally associated with a brake regeneration module, the
method further including operating the brake regeneration module in
conjunction with the brake actuator to regulate the measured
rotation rate of the wheel.
[0050] In some embodiments, the VCM-based brake system is a fluid
operated VCM-based brake system including a fluid pump disposed
within the VCM and adapted to pump pressurized brake fluid toward
the brake actuator, at least one fluid line adapted to provide
fluid communication between the fluid pump and the brake actuator,
and at least one valve disposed along the fluid line. In such
embodiments, activating the brake actuator includes activating the
fluid pump to pump pressurized brake fluid toward the brake
actuator, via the fluid line, and setting the at least one valve to
a position in which the fluid pump and the brake actuator are in
fluid communication, allowing pressure build-up at the brake
actuator.
[0051] In some embodiments, the method further includes measuring a
fluid pressure within the brake actuator and based on the measured
fluid pressure, operating the fluid pump to regulate the fluid
pressure within the brake actuator.
[0052] In some embodiments, the VCM-based brake system further
includes a pressurized fluid accumulator in fluid communication
with the fluid pump and with the brake actuator, and the activating
of the fluid pump includes activating the fluid pump to provide
pressurized fluid to the pressurized fluid accumulator and allowing
pressurized fluid to flow from the pressurized fluid accumulator
toward the brake actuator.
[0053] In some embodiments, activating of the fluid pump to provide
pressurized fluid occurs independently of the activating of the
brake actuator.
[0054] According to another aspect of some embodiments of the
present invention there is provided a method of operating a Vehicle
Corner Module (VCM)-based brake system including at least one
control circuit, the VCM-based brake system including a brake
modulator and a pressure modulator, the VCM-based brake system
being disposed within a VCM, the method including:
[0055] pressurizing brake fluid and storing the pressurized brake
fluid in an accumulator of the pressure modulator;
[0056] at the control circuit, obtaining a measured brake fluid
pressure in a fluid line between the pressure modulator and a brake
actuator of the VCM-based brake system;
[0057] at the control circuit, obtaining a target fluid pressure
required in the fluid line;
[0058] comparing the measured brake fluid pressure to the target
fluid pressure;
[0059] in response to identifying that the measured brake fluid
pressure rate is higher than the target fluid pressure,
deactivating the brake actuator; and
[0060] in response to identifying that the measured brake fluid
pressure rate is higher than the target fluid pressure, activating
the brake actuator.
[0061] According to yet another aspect of some embodiments of the
present invention there is provided a method of servicing a
VCM-based brake system disposed within a VCM mounted onto a vehicle
platform of a vehicle, the VCM-based brake system being
mechanically decoupled from the vehicle platform, the method
including: [0062] detaching the VCM from the vehicle platform;
[0063] while the VCM is detached from the vehicle platform,
servicing the VCM-based brake system accommodated within the
VCM.
[0064] In some embodiments, the method further includes, during the
servicing of the VCM-based brake system, attaching a replacement
VCM including a replacement VCM-based brake system to the vehicle
platform and operating the vehicle using the replacement VCM-based
brake system.
[0065] In some embodiments, the servicing of the VCM-based brake
system occurs at a location remote from the vehicle platform. In
some embodiments, the VCM-based brake system is a hydraulic
VCM-based brake system, which is airtight and fluid-tight within
the VCM. In some embodiments, there is no fluid communication
between the hydraulic VCM-based brake system and the vehicle
platform when the VCM is connected to the vehicle platform.
[0066] Unless otherwise defined, all technical and/or scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which the invention pertains.
In the case of conflict, the specification, including any
definitions therein, will take precedence.
[0067] As will be appreciated by one skilled in the art, some
embodiments of the present invention may be embodied as a system,
method or computer program product. Accordingly, some embodiments
of the present invention may take the form of an entirely hardware
embodiment, an entirely software embodiment (including firmware,
resident software, micro-code, etc.) or an embodiment combining
software and hardware aspects that may all generally be referred to
herein as a "circuit," "module" or "system."
[0068] Furthermore, some embodiments of the present invention may
take the form of a computer program product embodied in one or more
computer readable medium(s) having computer readable program code
embodied thereon. Implementation of the method and/or system of
some embodiments of the invention can involve performing and/or
completing selected tasks manually, automatically, or using a
combination thereof. Moreover, according to the actual
instrumentation of embodiments of the disclosed technology,
selected tasks may be implemented by hardware components, software
components, firmware components, or by a combination thereof, e.g.,
using an operating system.
[0069] For example, hardware for performing selected tasks of
embodiments of the disclosed technology may be implemented as a
chip or a circuit. Selected tasks of embodiments of the disclosed
technology may be implemented as a plurality of software
instructions stored in a computer readable storage medium and
executed by a processor using any suitable operating system. One or
more tasks according to embodiments of the disclosed technology may
be performed by a processor, such as a computing platform,
executing instructions. Optionally, the processor may be associated
with a volatile or non-volatile memory for storing instructions
and/or data, for example, a magnetic hard-disk and/or removable
media. In some embodiments, a computing device, processor, circuit,
or controller may be associated with a network connection, or a
network interface. In some embodiments, a computing device,
processor, circuit, or controller may be associated with an output
interface such as a display and/or an input interface such as a
keyboard or mouse.
[0070] Any combination of one or more computer readable medium(s)
may be utilized for some embodiments of the disclosed technology.
The computer readable medium may be a computer readable signal
medium or a computer readable storage medium.
[0071] A computer readable storage medium may be, for example, an
electronic, magnetic, optical, electromagnetic, infrared, or
semiconductor system, apparatus, or device, or any suitable
combination thereof. More specific examples of computer readable
storage media include an electrical connection having one or more
wires, a portable computer diskette, a hard disk, a random access
memory (RAM), a read-only memory (ROM), an erasable programmable
read-only memory (EPROM or Flash memory), an optical fiber, a
portable compact disc read-only memory (CD-ROM), an optical storage
device, a magnetic storage device, or any suitable combination
thereof. In the context of the disclosed technology, a computer
readable storage medium may be any tangible medium that can contain
or store a program for use by, or in connection with, an
instruction execution system, apparatus, or device, such as a
processor.
[0072] A computer readable signal medium may include a propagated
data signal with computer readable program code embodied therein,
for example, in baseband or as part of a carrier wave. Such a
propagated signal may take any of a variety of forms, including an
electromagnetic signal, an optical, or a combination thereof. A
computer readable signal medium may be any computer readable medium
that is not a computer readable storage medium and that can
communicate, propagate, or transport a program for use by, or in
connection with, an instruction execution system, apparatus, or
device, such as a processor.
[0073] Program code embodied on a computer readable medium and/or
data used thereby may be transmitted using any appropriate medium,
including wireless, wireline, optical fiber cable, RF, transmission
or communication, or any combination thereof.
[0074] Computer program code for carrying out operations of
embodiments of the disclosed technology may be written in any
combination of one or more programming languages. The program code
may execute entirely locally, partly locally, as a stand-alone
software package, partly locally and partly remotely, or entirely
remotely, such as on a remote computer, server, or in the Cloud.
The remote computing device may communicate may be connected with
the local computing device via any suitable network, including a
local area network (LAN) or a wide area network (WAN), or the
connection may be via an external computer (for example, through
the Internet using an Internet Service Provider).
[0075] Some embodiments of the disclosed technology may be
described with reference to flowcharts and/or block diagrams. It
will be understood that each block of a flowchart and/or block
diagrams, or combinations of such blocks, may be implemented as
computer program instructions, which, when executed, implement the
functions or actions specified in the block(s) of the flowchart
and/or block diagram. Some of the methods described herein are
generally designed only for use by a computer and may not be
feasible or practical for performing purely manually, by a human
expert. A human expert who wanted to manually perform similar
tasks, such as controlling brake operation, might be expected to
use completely different methods, e.g., making use of expert
knowledge and/or the pattern recognition capabilities of the human
brain, which would be vastly more efficient than manually going
through the steps of the methods described herein.
[0076] As used herein, the terms "comprising", "including",
"having" and grammatical variants thereof are to be taken as
specifying the stated features, integers, steps or components but
do not preclude the addition of one or more additional features,
integers, steps, components or groups thereof. These terms
encompass the terms "consisting of" and "consisting essentially
of".
[0077] As used herein, the term "computing device" relates to any
device having a processing unit into which it is possible to load
or install code that can be executed by the processing unit. The
loading or installation of the code may be possible even while the
device is operative in the field, or may be possible only in the
factory.
[0078] As used herein, the terms "network" and "computing network"
relate to a collection of computing devices and peripheral devices
which are all connected to common communication means that allow
direct communication between any two of the devices without
requiring passing the communicated data through a third device. The
network includes both the connected devices and the communication
means. A network may be wired or wireless or partially wired and
partially wireless.
[0079] As used herein, the term "or" is a logical operator
combining two Boolean input conditions into a Boolean compound
condition, such that the compound condition is satisfied if and
only if at least one of the two input conditions is satisfied. In
other words, if condition C=condition A or condition B, then
condition C is not satisfied when both condition A and condition B
are not satisfied, but is satisfied in each of the following cases:
(i) condition A is satisfied and condition B is not satisfied, (ii)
condition A is not satisfied and condition B is satisfied, and
(iii) both condition A and condition B are satisfied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] Some embodiments of the invention are herein described, by
way of example only, with reference to the accompanying drawings.
With specific reference now to the drawings in detail, it is
stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of embodiments of the
invention. In this regard, the description taken with the drawings
makes apparent to those skilled in the art how embodiments of the
invention may be practiced. In the drawings:
[0081] FIG. 1A is a schematic block diagram of a VCM and a vehicle
platform adapted to have the VCM mounted thereon, according to an
embodiment of the disclosed technology;
[0082] FIG. 1B is a schematic block diagram of a brake system
within a VCM, according to some embodiments of the disclosed
technology;
[0083] FIG. 2 is a schematic block diagram of a VCM-based brake
system according to some embodiments of the disclosed
technology;
[0084] FIGS. 3A, 3B, and 3C are schematic block diagrams of a
VCM-based brake system according to some embodiments of the
disclosed technology;
[0085] FIG. 4 is a flowchart of a method of operating a hydraulic
VCM-based brake system, according to some embodiments of the
disclosed technology;
[0086] FIGS. 5A and 5B are, respectively, mechanical and electrical
schematic block diagrams of a VCM-based brake system functionally
associated with, or including, a VCM-pressure modulator, according
to some embodiments of the disclosed technology;
[0087] FIGS. 6A and 6B together are a flowchart of a method of
operating a hydraulic VCM-based brake system including, or
associated with, a VCM-pressure-modulator, according to some
embodiments of the disclosed technology;
[0088] FIGS. 7A and 7B are schematic block diagrams of a VCM-based
brake system having brake regeneration according to some
embodiments of the disclosed technology; and
[0089] FIGS. 8A and 8B is are flowchart of methods for operating a
VCM-based brake system having a brake regeneration functionality,
according to some embodiments of the disclosed technology.
DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION
[0090] The present invention, in some embodiments, relates to
vehicle brake systems and particularly to vehicle brake systems
integrated in Vehicle Corner Modules (VCMs), and to methods of
operating and servicing such brake systems.
[0091] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not
necessarily limited in its application to the details of
construction and the arrangement of the components and/or methods
set forth in the following description and/or illustrated in the
drawings and/or the Examples. The invention is capable of other
embodiments or of being practiced or carried out in various
ways.
Overview
[0092] Vehicle brake systems typically have components distributed
between a wheel assembly and the vehicle platform. Brake actuation
requires transferring of power from the vehicle platform to the
wheel assembly. For example, hydraulic brake actuation requires
transfer of hydraulic fluid pressure, via fluid lines, from a fluid
reservoir mounted onto the vehicle platform, to the wheel assembly.
In some cases, the brake system has two brake circuits, to provide
redundancy for safety purposes.
[0093] Distributed braking systems having some components disposed
on the vehicle platform, and other components disposed close to the
wheel, are disadvantageous for several reasons. First, long
connection lines are required to connect the components on the
vehicle platform to the components on the wheel assemblies.
Additionally, particularly in hydraulic systems, replacement of
brake system components requires detachment of the hydraulic
connection line, which can lead to hazardous introduction of air
into the hydraulic lines, and damage to the brake system.
[0094] As used herein, the term/phrase vehicle platform means a
platform of the vehicle, such as the chassis or a reference frame
to which other components of the vehicle are attached (e.g.
suspension system, vehicle body, electrical control unit, and power
source). Servicing the brake system requires access to the vehicle
platform as well as to the wheel, or vehicle corner, assemblies.
This may complicate servicing and extend the downtime of the
serviced vehicle.
[0095] In accordance with some embodiments of the disclosed
technology, a VCM-based brake system is confined within the VCM,
possibly receiving electronic input from a controller mounted on
the vehicle platform. It is a feature of such embodiments that
servicing of such a brake system may be carried out away from the
vehicle platform, for example after another VCM has been placed on
the vehicle, maintaining the operational ability of the vehicle
during servicing of the brake system. This significantly simplifies
servicing of the vehicle, and reduces downtime of the vehicle for
servicing and maintenance thereof.
[0096] It is another feature of the disclosed technology that
safety is enhanced, by increasing redundancy of the brake system to
4 independent brake circuits. In accordance with some embodiments,
the four independent brake circuits may include at least two
different types of brake circuits, having at least one different
characteristic therebetween.
[0097] It is a further feature of the disclosed technology that the
VCM-based brake system is independent of the car model of type,
such that a VCM may be functionally suitable for use with multiple
car models or types.
[0098] According to an embodiment of the disclosed technology,
there is provided a VMC-based brake system, adapted to be assembled
within a VCM, between the vehicle platform (e.g. chassis, wheel
well) and a wheel assembled to the VCM. The VCM-based brake system
includes a brake-control-circuit (e.g. one or more brake
controller) adapted to receive data about a rotation rate of the
wheel assembled to the VCM. The data may be measured by a rotation
rate sensor, functionally associated with, or integrated within,
the VCM. In some embodiments, the brake-control-circuit is
functionally associated with a speed control circuit (SCC), which
outputs a target wheel rotation rate.
[0099] In some embodiments, the VCM-based brake system includes a
brake actuator (e.g. a brake caliper) that regulates the rotation
rate of the wheel. The brake actuator is functionally associated
with the brake-control-circuit, and receives actuation inputs from
the brake-control-circuit. In some embodiments, the brake actuator
may be directly or indirectly connected to the
brake-control-circuit.
[0100] In some embodiments, the VCM-based brake system includes one
or more brake power sources, which may be disposed within the VCM,
and which provide operational power to the brake actuator and/or to
the brake-control-circuit. In some embodiments, the brake power
source includes a fluid pump, a fluid source, an electrical power
source (e.g. a battery), or a combination thereof. In some
embodiments, the brake-control-circuit is adapted to receive brake
fluid pressure values, measured at or adjacent components of the
VCM-based brake system, disposed on the VCM.
[0101] According to some embodiments, the VCM-based brake system
includes one or more brake-interface-circuits adapted to allow an
interface between the brake-control-circuit and one or more control
circuits external to the VCM, such as control circuits mounted onto
the vehicle platform or cloud based control circuits. In some
embodiments, the brake-interface-circuit is integrated within a VCM
connector, interfacing between the VCM and the vehicle
platform.
[0102] According to an aspect of the current invention, there is
provided a VCM-based brake system, comprising a brake controller
assembled within a VCM of a vehicle. The brake controller includes
one or more valves in fluid communication with a brake actuator to
regulate delivery, maintenance, and release of fluid between the
brake actuator, a fluid source, and a fluid pump.
[0103] According to some embodiments, the VCM-based brake system
includes a fluid source in fluid communication with the brake
controller. In some embodiments, the fluid source includes a local
reservoir, disposed within the VCM, that substitutes a master
cylinder traditionally located on the vehicle platform. In some
embodiments, the VCM-based brake system includes a hydraulic fluid
pump, which acts as a power source for actuating the brake
actuator. In some embodiments, the fluid pump is in fluid
communication with the brake controller and the fluid source.
[0104] It is a particular feature of the disclosed technology that
when the hydraulic lines are disposed within the VCM, mounting of
the VCM to the vehicle platform connects the VCM-based brake system
to the vehicle platform, in an operational state. Additionally,
connection and disconnection of the VCM from the vehicle platform
can be carried out without disconnecting fluid lines or exposing
fluid line to air contamination. The short distance between
components of the VCM-based brake may increase system efficiency
and performance of fluid based brake systems, such as hydraulic
and/or pneumatic systems.
[0105] It is a particular feature of the disclosed technology that,
because of the decoupling between the vehicle platform and the
VCM-based brake system, servicing and testing of the VCM-based
brake system may be carried out away from the vehicle platform. For
example, diagnosing and/or calibrating of the VCM-based brake
system may be done on a rig without having the vehicle platform
available.
[0106] An aspect of the invention is related to an ESC modulator
integrated within a VCM.
[0107] According to some embodiments, the ESC module of a vehicle
includes an ESC control circuit adapted to control the ESC
modulator. In some embodiments, the ESC control circuit is
assembled on the vehicle platform. In some embodiments, the ESC
control circuit is assembled within one or more of the VCMs of the
vehicle.
[0108] According to some embodiments, in which the VCM-based brake
system is a fluid operated brake system, fluid pressure for
actuating the brake actuator is regulated by a single fluid pump
disposed within the VCM, at least for brake actions initiated for
the purpose of reducing the vehicle speed and/or for regulating the
rotation rate of a wheel hub initiated by a computing unit (e.g.
ESC).
[0109] An aspect of the current invention is related to providing
ESC functionality by intercommunication between VCMs, without
requiring data from a computing unit disposed on the vehicle
platform. In some embodiments, the vehicle platform is devoid of an
ESC controlling unit. In some embodiments, communication between
VCMs is complemented by communication with an external computer,
for example in fully or partially autonomous vehicles.
[0110] According to some embodiments, ESC modules disposed one the
VCM intercommunicate. In some embodiments, the ESC modules are
controlled solely by the ESCs within the VCMs, and do not receive
control signals from a controller located on the vehicle platform.
Inter communication between mounted VCMs may be between any two or
more VCMs, including a pair of front or rear VCMs, between VMCs
located on the same side of the vehicle, or between all the
VCMs.
[0111] Reference is now made to FIG. 1A, which is a schematic block
diagram of a VCM and a vehicle platform adapted to have the VCM
mounted thereon, according to an embodiment of the disclosed
technology.
[0112] As seen in FIG. 1A, a vehicle platform 10, which is adapted
to have a vehicle capsule mounted thereon, includes a vehicle
reference-frame 12, having VCM-connection interfaces 14 adapted for
connection to VCMs.
[0113] Vehicle platform 10 may include one or more electronic
subsystems 16 mounted onto reference frame 12, which may include a
power supply of the vehicle, a control circuit of the vehicle, a
computerized controller of the vehicle, a network bus of the
vehicle, and a network interface of the vehicle. In some
embodiments, reference-frame 12 may also have attached thereto
front and/or rear bumpers 19.
[0114] A VCM 20, for regulating motion of the vehicle, is
connectable to reference frame 12. According to some embodiments,
VCM 20 includes a sub-frame 22, including a vehicle-connection
interface 24 adapted for reversible mechanical connection to
VCM-connection interface 14 of reference frame 12. VCM 20 further
includes a wheel-hub assembly 26, adapted to have a wheel 28
mounted thereon. Sub-frame 22 has mounted thereon one or more
subsystems of the vehicle, each comprising mechanical and/or
electrical components. The subsystems may also be attached to
wheel-hub assembly 26.
[0115] The subsystems included in the VCM may include a drive
system 30, a steering system 32, a suspension system 34, and/or a
brake system 36. Sub-frame 22 may also include a VCM-controller 38,
adapted to control operation of one or more of systems 30, 32, 34,
and 36, and/or to communicate with one or more electronic
subsystems 16 of the vehicle, such as with a computerized
controller or a network interface of the vehicle.
[0116] Drive system 30 may include any or all of the mechanical
and/or electrical components required for actuating a drive shaft
to rotate wheel 28, or other wheels of the vehicle, to drive the
vehicle, including, and not exhaustively: an electric drive motor,
a driveshaft turned by the motor, and gearing assemblies to
transmit the rotation to the wheel including, optionally, a
single-hear or multi-gear transmission, as well as sensors such as
a wheel speed sensor (in a non-limiting example, a rotary encoder).
In some embodiments, the drive motor is included in the VCM, and in
some embodiments, the drive motor is on the vehicle, e.g.,
installed on reference frame 12. In some embodiments, the drive
motor is mounted on sub-frame 22 and thereby is a sprung mass.
[0117] In embodiments, VCM-controller 38 is adapted to regulate an
output of the motor and/or a rotational velocity of wheel 28 and/or
a selection of a transmission gear, in response to instructions
received via electrical inputs from the vehicle, e.g., from a
driver-operated drive mechanism (e.g. an accelerator pedal) or an
autonomous driving unit. In embodiments, the instructions include,
for example, a current and a voltage for actuating the electric
drive motor.
[0118] In embodiments, drive system 30 can be used in a
regenerative braking scheme, as explained in further detail
hereinbelow.
[0119] Steering system 32 may include any or all of the mechanical
and/or electrical components required for steering, i.e., pivoting
the wheel of the vehicle around a steering axis, including, and not
exhaustively: a steering motor, a steering actuator, steering rods,
steering system controller or control unit, steering inverter and
wheel-angle sensor.
[0120] In some embodiments, VCM-controller 38 receives steering
instructions as electrical (including electronic) inputs from the
vehicle, e.g., from a driver-operated steering mechanism or an
autonomous steering unit, and carries out the instructions by
causing, responsively to the received instructions, the motion of a
steering rod, e.g., via a steering actuator, to effect the turning
of the wheel, for example, by regulating a current and voltage
transmitted to the steering actuator and/or transmitting high-level
instructions to a steering-system controller. The steering motor,
actuator and/or inverter can receive electrical power from an
external power source (`external` meaning external to the VCM),
such as a power supply installed in or on the reference frame.
[0121] Suspension system 34 may optionally include an active
suspension system controllable by the VCM-controller 38 (e.g., via
a suspension-system control unit).
[0122] Brake systems 36 according to embodiments of the present
invention is described hereinbelow with respect to FIGS. 1B to
4B.
[0123] In some embodiments, VCM controller 38 is configured to
regulate an output of the braking system, e.g., cause a braking
action, in response to instructions received via electrical inputs
from the vehicle, e.g., from a driver-operated braking mechanism
(e.g. a brake pedal) or an autonomous braking unit.
[0124] In some embodiments, the plurality of VCM subsystems in VCM
20 includes all of systems 30, 32, 34, and 36. In other
embodiments, the plurality of VCM systems in a given VCM 20 may
include two or three of the systems.
[0125] Reference is now made to FIG. 1B is a schematic block
diagram of a brake system within a VCM, according to some
embodiments of the disclosed technology.
[0126] As seen in FIG. 1B, VCM-based brake system 36, is adapted to
be accommodated within VCM 20, between vehicle platform 12 and
wheel 28 assembled to VCM 20.
[0127] VCM-based brake system 36 includes a brake-control-circuit
(e.g. one or more brake controller) 102 adapted to receive data
about a rotation rate of wheel 28. In some embodiments, the
brake-control-circuit may form part of the VCM-controller 38. The
rotation rate data may be measured by a rotation rate sensor 104,
which may form part of VCM 20.
[0128] VCM-based brake system 36 includes a brake actuator (e.g. a
brake caliper) 106, adapted to regulate the rotation rate of wheel
28, based on actuation inputs received from brake-control-circuit
102. In some embodiments, brake actuator 106 is connected directly
to brake-control-circuit 102 to receive the actuation inputs
therefrom. In other embodiments, brake actuator 106 is functionally
associated with brake-control-circuit 102, for example by wireless
communication.
[0129] VCM-based brake system 36 may further include one or more
brake power sources 107, disposed within VCM 20. The brake power
source(s) 107 is adapted to provide operational power to brake
actuator 106 and/or to brake-control-circuit 102. In some
embodiments, vehicle platform 12 may include a secondary or
additional power source, not explicitly shown. In some embodiments,
the brake power source may include a fluid pump, a fluid source
(e.g. brake fluid reservoir, fluid cylinder), an electrical power
source (e.g. a battery), or a combination thereof, as explained in
further detail herein.
[0130] According to some embodiments, VCM-based brake system 36
includes one or more brake-interface-circuits 108 adapted to
provide an interface between brake-control-circuit 102 and one or
more vehicle control circuits mounted outside VCM 20. For example,
brake-interface-circuit 108 may provide an interface with a vehicle
controller 116 mounted onto vehicle platform 12. In some
embodiments, brake-interface-circuit 108 form part of vehicle
connection interface 24. In some embodiments,
brake-interface-circuit 108 is adapted to connect to a platform
connector 118, which may form part of VCM-connection interface 14
mounted onto vehicle platform 12. In some embodiments,
brake-interface-circuit 108 includes one or more transmitters to
establish wireless connection with circuits outside VCM 20, such as
with a vehicle controller mounted onto the vehicle platform.
[0131] According to some embodiments, vehicle platform 12 includes
a plurality of platform connectors 118. In some embodiments, two or
more of platform connectors 118 are interconnected by a
platform-VCM bus 119. In some embodiments, platform-VCM bus 119 is
used for communication between computing circuits assembled within
multiple VCMs 20.
[0132] According to some embodiments, brake-control-circuit 102 is
functionally associated with a speed-control-circuit 127, which
outputs a target rotation rate. In some embodiments,
speed-control-circuit 127 forms part of vehicle controller 116, and
is connected to vehicle platform 12. In some embodiments, a single
speed-control-circuit 127 may provide inputs to, or control, brake
system 36 of one or more VCMs 20. In some other embodiments,
speed-control-circuit 127 may form part of VCM-based brake system
36, such that target rotation rate profile is determined by VCM 20.
In some such embodiments, speed-control-circuit 127 is functionally
associated with (e.g. via brake-interface-circuit 108) to a circuit
disposed on vehicle platform 12, such as vehicle controller 116.
The speed-control-circuit may be connected to controller 116, or
may communicate therewith by wireless communication.
[0133] In some embodiments, speed-control-circuit 127 may include a
storage unit 128 for storing a target rotation rate profile. In
some embodiments, speed-control-circuit 127 may include a rotation
rate feedback loop comparing a measured rotation rate profile of
the wheel to the target rotation rate profile, as described in
further detail hereinbelow. In some embodiments,
speed-control-circuit 127 may include a transmitter for providing
the target rotation rate profile to brake-control-circuit 102.
[0134] In some embodiments, at least a portion of
speed-control-circuit 127 may be form part of another device (not
explicitly shown) that controls the kinematic profile of wheel. For
example, the device may control the profile of the wheel when VCM
20 is detached from the vehicle platform, e.g. on a servicing or
testing rig. As another example, the device may control the profile
of the wheel when the vehicle is controlled by a control unit which
is remote from the vehicle.
[0135] In some embodiments, speed-control-circuit 127 includes some
sub-circuits disposed within VCM-based brake system 36, and other
sub-circuits disposed remotely to VCM-based brake system 36, such
that the sub-circuits can communicate with one another via one or
more suitable communication channel(s).
[0136] Brake actuator 106 may be friction based, e.g. a disk brake
caliper or a drum brake. Brake actuator 106 may be non-friction
based, such as an actuator using a magnetic field, fluid, and the
like. In some embodiments, brake actuator 106 is electrically
actuated, for example by receipt of an electrical input from
brake-control-circuit 102 or from another control circuit. In some
embodiments, brake actuator 106 is mechanically actuated, such as
by fluid. For to example, brake actuator 106 may be hydraulic or
pneumatic.
[0137] In some embodiments, VCM-based brake system 36 regulates the
kinematic profile of wheel 28 by reducing, and/or maintaining the
rotation rate of the wheel. In some embodiments, regulating the
kinematic profile includes reducing, increasing, and/or maintaining
a change in the rotation rate (e.g. accelerating, decelerating the
rotation rate). In some embodiments, the kinematic profile may be
regulated by brake-control-circuit 102. In some embodiments, the
kinematic profile may be regulated by speed-control-circuit 127 and
by brake-control-circuit 102. A method for regulating the kinematic
profile of the wheel is described hereinbelow.
[0138] In some embodiments, rotation rate sensor 104 is a
wheel-speed sensor, measuring one or more of a rotation speed, and
acceleration/deceleration of rotation of wheel 28. As discussed
hereinabove, rotation rate sensor 104 is disposed within VCM 20,
for example by coupling thereof to wheel hub 26, to the drive
shaft, or to the powertrain.
[0139] In some embodiments, VCM-based brake system 36 may include a
brake pressure sensor 109 adapted to sense and/or measure a
pressure applied by brake actuator 106 to regulate the rotation
rate of wheel 28 (e.g. pressure applied by a brake disc or
caliper). The measured pressure may be used by
brake-control-circuit 102 and/or by speed-control-circuit 127 to
determine whether additional brake actuation is required, as
explained in further detail hereinbelow. In some embodiments, when
the applied brake pressure is maximal, but the rate of rotation of
wheel 28 is still too high, the rotation rate of the wheel may be
further reduced using other methods, such as steering of one or
more wheels, actuation of a brake regeneration system, activating a
brake emergency system, and/or actuating a wheel motor, as
explained hereinbelow.
[0140] In accordance with an embodiment of the disclosed
technology, mounting of VCM 20 to vehicle platform 12, connects
VCM-based brake system 36 to the vehicle platform, enabling the
VCM-based brake system to immediately be operative. In some such
embodiments, all components required to apply a braking force to
wheel 28 are disposed within VCM 20. As such, no fluid connections
are required in order to allow the brake system to be operative. In
such embodiments, components of brake system 36 are all disposed at
a short distance from each other, thereby increasing the efficiency
and performance of the brake system, and improving access of an
operator to the brake system components.
[0141] In accordance with some embodiments of the disclosed
technology, servicing and testing of VCM-based brake system 36 may
be carried-out when the VCM is distant from vehicle platform 12,
for example following detachment of VCM 20 from the vehicle
platform, as explained in further detail hereinbelow. This may
further contribute to reducing downtime of vehicle 10 due to
maintenance, since the vehicle operated using a replacement VCM
during maintenance of VCM 20 and of VCM-based brake system 36.
[0142] In some embodiments of the disclosed technology, the cooling
rate (thermal transfer) of brake controller 102 by air, is
improved, relative to prior art systems in which the brake
controller is disposed on the vehicle platform. This is because the
brake controller 102 is exposed to air flow through VCM 20, where
airflow may be faster than within vehicle platform 12.
[0143] In some embodiments, independent VCM-based braking systems
36 are installed in each of VCMs 20 mounted onto the vehicle
platform 12. In such embodiments, vehicle braking safety is
enhanced by increasing the redundancy to braking systems in the
vehicle.
[0144] The independent nature of the VCM-based braking systems 36
allows for different types of braking systems 36 to be installed
within different VCMs of the same vehicle. For example, the braking
systems 36 installed in the front VCMs of the vehicle may have a
different braking profile than the braking systems 36 installed in
rear VCMs of the vehicle. As another example, the braking profile
of a braking system within each VCM may be determined, at least in
part, by other components or subsystems of the VCM. As such, a
braking system 36 in a VCM including a steering system 32, may have
a different braking profile than a similar braking system in a VCM
which does not include the steering system.
[0145] The independent nature of the VCM-based braking systems 36,
and their decoupling from the vehicle platform 12, also enables a
VCM to be generic and suitable for use with different types or
models of vehicles.
Hydraulic VCM-Based Brake System
[0146] Reference is now made to FIG. 2, which is a schematic block
diagram of a hydraulic VCM-based brake system, according to some
embodiments of the disclosed technology. It will be appreciated
that though the description herein relates to a hydraulic VCM-based
brake system, the disclosed technology is applicable also to
pneumatic braking systems.
[0147] As is known in the art, hydraulic brake actuation requires
the transfer of hydraulic fluid, via fluid lines, from a source
reservoir. Typically, the source reservoir is mounted onto the
vehicle platform, and the fluid lines extend from the platform to
the brake system(s), adjacent the wheels. In vehicles, in which a
hydraulic brake system has some components disposed within the
corner assembly and other components mounted onto the vehicle
platform (e.g. to the master cylinder, pump, and brake modulator),
access and interaction with the vehicle platform as well as with
the brake actuator at the wheel assembly is required for servicing
of the vehicle and the brake system. Servicing of such a system
typically requires disconnecting the brake system from the vehicle
platform. Consequently, servicing of such distributed hydraulic
brake systems is complicated, particularly when ensuring safe
operation of the brake system, for example by ensuring that the
hydraulic lines are devoid of air.
[0148] VCM-based brake systems according to the disclosed
technology, as described hereinabove and as shown specifically in
FIG. 2, overcome the deficiencies of the prior art systems, but
ensuring that all components of the brake system are disposed
within the VCM. As a result, the brake system is completely
mechanically decoupled from the vehicle platform. Additionally, the
hydraulic system is fluid tight and air tight within the VCM,
regardless of connection or disconnection of the VCM to the vehicle
platform.
[0149] As seen in FIG. 2, VCM 20 includes a hydraulic VCM-based
brake system 236, adapted to be accommodated within VCM 20, between
vehicle platform 12 and wheel 28.
[0150] Hydraulic VCM-based brake system 236 may be an embodiment of
VCM-based brake system 36 of FIG. 1B, wherein brake actuator 206 is
powered by hydraulic fluid. Brake-control-circuit 202, also termed
herein a brake controller, includes one or more valves in fluid
communication with brake actuator 206.
[0151] Hydraulic VCM-based brake system 236 includes a power
source, equivalent to power source 107 of VCM-based brake system
36. However, the power source of hydraulic VCM-based brake system
236 includes two components, a hydraulic fluid source 210, and a
hydraulic fluid pump 212. At least one of fluid source 210 and
fluid pump 212 is disposed within VCM 20. However, in some
embodiments, both fluid source 210 and fluid pump 212 are both
disposed within the VCM.
[0152] In some embodiments, fluid source 210 is in fluid
communication with brake controller 202. In some embodiments, fluid
source 210 includes a local reservoir, within VCM 20. The local
reservoir is adapted to replace a master cylinder or reservoir,
which, in prior art systems, is located on vehicle platform 12.
[0153] In some embodiments, fluid pump 212 acts as a power source
for actuating operation of brake actuator 206. Fluid pump 212 is in
fluid communication with brake controller 202 and with fluid source
210, for example by hydraulic fluid lines, which may also be
disposed within VCM 20. In some embodiments, pressurizing of fluid
in the hydraulic system, for operation of brake actuator 206,
occurs only within VCM 20. In such embodiments, the pressure is not
applied from a component mounted onto vehicle platform 12. In some
embodiments, fluid pump 212 includes a local reservoir, within VCM
20. The local reservoir is adapted to replace a main pump
reservoir, which, in prior art systems, is located on vehicle
platform 12.
[0154] In some embodiments, pump 212 functions as a pressure
increasing pump, and is adapted to increase fluid pressure in a
fluid line towards brake actuator 206). In some embodiments, pump
212 is bi-directional, and in addition to being adapted to increase
pressure, it is further adapted to be operative decrease fluid
pressure in the fluid line, for example to generate a negative
pressure in brake actuator 206.
[0155] In some embodiments, ESC functionality is adapted to be
integrated with, or form part of, brake-control-circuit 202.
Consequently, one or more of ESC modulators and
modulator-control-circuit(s) may be integrated within
brake-control-circuit 202.
[0156] In some embodiments, VCM 20 includes a sub-frame, similar to
sub-frame 22 of FIG. 1A, adapted to be attached to a reference
frame of vehicle platform 12. In some embodiments, fluid source 210
is mounted onto the sub-frame. In some embodiments, fluid pump 212
is assembled to the sub-frame. In some such embodiments, fluid
source 210 and/or fluid pump 212 function, on the sub-frame, as a
sprung mass, reducing vibrations caused by loads applied to these
components. Additionally, mounting of fluid source 210 and/or fluid
pump 212 onto the sub-frame may increase air-flow around the fluid
source and fluid pump, which may assist in chilling fluid source
210 and/or fluid pump 212 during operation thereof.
[0157] In some embodiments, brake controller 202 includes a brake
pressure modulator 214, adapted to regulate delivery, maintenance,
and release of fluid or fluid pressure between brake actuator 206,
fluid source 210, and fluid pump 212.
[0158] In some embodiments, one or more components of hydraulic
VCM-based brake system 236 may be electrically connected to each
other or may communicate with each other, whether in a wired
connection/communication or wirelessly. For example, fluid pump 212
may be connected to brake controller 202 by fluid and electrical
connections.
[0159] In some embodiments, hydraulic VCM-based brake system 236
includes one or more brake-interface-circuits 208 adapted to allow
an interface between brake-control-circuit 202 and one or more
vehicle control circuits 116 mounted to vehicle platform 12. As
discussed hereinabove, vehicle control circuit 116 may include a
speed-control-circuit 127. In some embodiments, vehicle control
circuit 116 may further include a VCM-systems-control-circuit 130,
adapted to control systems of VCMs of the vehicle, and in some
embodiments, also adapted to control interactions between the VCMs
or the VCM systems. Typically, the vehicle control circuit 116, and
specifically the VCM-systems-control-circuit 130, communicate with,
and provide inputs to, control circuits mounted within the VCMs,
such as the VCM controller 38 of FIG. 1A, or brake-control-circuit
202. Vehicle control circuit(s) 116 may be powered by a vehicle
power source 131, mounted onto vehicle platform 12.
[0160] In some embodiments, as shown for example in FIG. 2A,
brake-interface-circuit 208 forms part of a vehicle-connection
interface, similar to vehicle-connection interface 24 of FIG. 1A.
In some embodiments, brake-interface-circuit 208 includes one or
more transmitters or transceivers, adapted to establish wireless
connection with circuits external to VCM 20.
[0161] In some embodiments, VCM 20 includes a VCM controller 215,
similar to VCM controller 38 of FIG. 1B. Inputs relating to a
rotation profile of wheel 28 are received by VCM-controller 38,
which is adapted to provide operational inputs to one or more of
brake controller 202 and fluid pump 212.
[0162] As mentioned hereinabove, hydraulic VCM-based brake system
236 may be an embodiment of VCM-based brake system 36, and may
include components and functionalities described with respect to
FIG. 1B, such as a rotation rate sensor 203 similar to rotation
rate sensor 104 and a brake pressure sensor similar to brake
pressure sensor 107.
[0163] It is a particular feature that hydraulic VCM-based brake
system according to the disclosed technology have shorter fluid
transmission lines, or a reduced number of fluid transmission
lines, relative to prior art systems in which the brake system is
distributed between the vehicle platform and the VCM. The
shortened/reduced fluid transmission lines allow for a reduced
overall amount of hydraulic fluid within a closed brake system, and
increased brake system efficiency and performance. Furthermore, the
reduced volume of hydraulic fluid enables operation of the system
using smaller, and weaker pumps.
[0164] Additionally, and as mentioned herein, according to the
disclosed technology, the brake system is completely mechanically
decoupled from the vehicle platform. Additionally, the hydraulic
system is fluid tight and air tight within the VCM, regardless of
connection or disconnection of the VCM to the vehicle platform.
These aspects assist in maintenance of the to VCM and the vehicle
in general, as discussed.
[0165] As discussed hereinabove, the VCM-based brake system of the
disclosed technology allows for greater redundancy and increased
safety of the braking system. This is particularly true for
hydraulic systems. As is well known in the art, hydraulic brake
systems often malfunction because of heated brake fluid or gas
bubbles mixed in the fluids within the fluid transmission lines. In
prior art hydraulic systems, in which the brake fluid and fluid
lines are shared between multiple brake actuators or circuits, such
deficiencies affect all the brake actuators sharing the fluid, or
fluid lines, which may result in reducing the brake performance of
the vehicle. The independence of VCM-based brake systems for the
disclosed technology from one another, and specifically the
independent fluid transmission components, ensure that if the
quality of fluid is reduced in one of the reservoirs, this only
affects one brake system of one VCM, and the remaining brake
systems function properly. Additionally, the reservoir and pump
disposed within the VCM are more exposed to airflow, thereby
reducing the chance of the fluid overheating.
[0166] Referring now to FIGS. 3A, 3B, and 3C, which are schematic
block diagrams of a VCM-based brake system 336, according to some
embodiments of the disclosed technology. Brake system 336 may be an
embodiment of hydraulic VCM-based brake system 236 described
hereinabove with respect to FIG. 2, and may include similar
components, subsystems, and functionalities.
[0167] As seen in FIG. 3A, hydraulic VCM-based brake system 336
includes a brake modulator 352, adapted to control the operation of
brake actuator 306. In the illustrated embodiment, brake modulator
352 functions as a brake fluid supply modulator, and is adapted to
modulate the supply of braking fluid to the brake actuator 306.
[0168] As discussed hereinabove, hydraulic VCM-based brake system
336 is adapted to be disposed in a VCM 20 (FIG. 1A), which is
adapted to be mounted onto a vehicle platform 12 (FIG. 1A). The
vehicle platform is adapted to have multiple VCMs attached thereto.
As discussed herein, each VCM may include a dedicated VCM-based
brake system, which may be independent of the vehicle platform and
of the other VCMs. In some embodiments, each VCM-based brake system
includes, or is functionally associated with, a dedicated brake
modulator 352 as described herein. Typically, each modulator 352 is
adapted to receive control inputs from a brake-control-circuit 302,
similar to brake-control-circuit 202 of FIG. 2. Additionally or
alternatively, one or more of the brake modulator 352 is adapted to
receive control inputs from a central controller, such as control
circuit 116 (FIGS. 1B and 2) of the vehicle.
[0169] In the embodiments shown in FIGS. 3A and 3B, brake system
336 includes, a single-channel modulator 352. Modulator 352
includes one or more modulator valves, as described herein, and one
or more modulator control circuits 356 adapted to control the
modulator valves.
[0170] In some embodiments, control of VCM 20 is by one or more VCM
control loops. In some embodiments, the VCM control loops include a
brake control loop. In some embodiments, the brake control loop
includes brake controller 302 operating brake modulator 352, with
respect to inputs received by brake controller 302. For example,
inputs received by brake controller 302 may include a speed
reduction input signal, and an ESC input signal. A speed reduction
input signal may be initiated by a driver, for example depressing a
brake signal or pressing a suitably configured brake button, or by
an automated driving system identifying that speed reduction is
required. An ESC input signal may be initiated, for example, for
control of traction or stability, e.g. when road conditions are
hazardous or when initial loss of control is identified.
[0171] In some embodiments, hydraulic VCM-based braking system 336
is a brake-by-wire system. In such embodiments, braking operations
are actuated by an electrical input provided to the
brake-control-circuit 302. The electrical input may be initiated by
an automated system, for example by sensors identifying a need to
slow down the vehicle. The electrical input may also be initiated
by a driver, pressing a suitable brake button or depressing a brake
pedal.
[0172] It is a feature of the present invention, that as a result
of the decoupling of the brake system from the vehicle platform and
the use of brake-by-wire functionality, even if the driver presses
the brake pedal for an extended period, there is no locking of the
brake. Consequently, in the embodiments shown in FIGS. 3A to 3C,
the VCM-based braking system 336 does not require, and in some
embodiments is devoid of, a master cylinder and/or a fluid
accumulator upstream of the fluid pump, or altogether.
[0173] According to some embodiments, a single fluid pump 312 is
adapted to generate fluid pressure for actuating brake actuator
306. This is particularly true when the braking operation is for
the purpose of reducing the speed of the vehicle, or when
regulating of the rotation rate of the wheel hub is initiated by a
computing unit, such as an ESC functionality incorporated within
brake modulator 352 or brake controller 302.
[0174] It is a particular feature of the disclosed technology that
each brake modulator 352, which is disposed within VCM-based brake
system 336, is smaller than a prior art ESC modulator used for
typical ESC systems and provides at least the functionality of the
typical ESC systems. Additionally, brake modulator 352 has a
reduced number of valves relative to a prior art ESC modulator, and
thus may also require simpler control logic. In some embodiments,
brake modulator 352 may function as brake pressure modulator 214 of
FIG. 2, the brake pressure modulator having one or more valves in
fluid communication with brake actuator 306 to regulate fluid flow
between the brake actuator 306, fluid source 310, and fluid pump
312.
[0175] Turning specifically to FIG. 3A, in some embodiments, brake
modulator 352 includes two valves--a fluid inlet valve 357 and a
fluid release valve 358. Each of valves 357 and 358 has an open
operative orientation and a closed operative orientation. When in
the open operative orientation, fluid inlet valve 357 is adapted to
provide hydraulic fluid to, and increase the fluid pressure within,
brake actuator 306. By contrast, fluid release valve 358 is adapted
to release fluid from, and to reduce the fluid pressure within,
brake actuator 306 when it is in the open operative
orientation.
[0176] In some embodiments, fluid inlet valve 357 is a 2-port 2-way
valve, having inlet and outlet ports, and two positions. In some
embodiments, a first position 357a of inlet valve 357 is a pressure
buildup position, in which a pressure source (e.g. fluid pump 312)
is in fluid communication with brake actuator 306. In some
embodiments, a second position 357b of inlet valve 357 is a
pressure maintenance position, in which there is no fluid
communication between the pressure source and brake actuator 306,
preventing fluid from flowing between brake actuator 306 and fluid
source 310.
[0177] In some embodiments, such as in the illustrated embodiment
of FIG. 3A, inlet valve 357 is normally open, such that it is
normally in the pressure buildup position 357a. In other
embodiments, inlet valve 357 may be normally closed, such as it is
normally in the pressure maintenance position 357b.
[0178] In some embodiments, fluid release valve 358 is a 2-port
2-way valve, having inlet and outlet ports, and two positions. In
some embodiments, a first position 358a of fluid release valve 358
is a pressure maintenance position, in which there is no fluid
communication between brake actuator 306 and fluid source 310,
preventing fluid from flowing towards fluid source 310. In some
embodiments, a second position 358b of release valve 358 is a
pressure release position, in which brake actuator 306 is in fluid
communication with fluid source 310, and fluid can flow from the
brake actuator to the reservoir. In some embodiments, fluid release
valve 358 is normally closed, such that it is normally in the
pressure maintenance position 358a.
[0179] In some embodiments, valves 357 and 358 are transitioned
between the open operative orientation and the closed operative
orientation by solenoids. In some embodiments,
modulator-control-circuit(s) 356 is connected to, or functionally
associated with, the solenoids controlling operation of valves 357
and 358 and synchronizes their operation. In some embodiments,
valves 357 and 358 are proportional valves.
[0180] Turning now to FIG. 3B, it is seen that in some embodiments,
brake modulator 352 includes a single valve 359, adapted to control
fluid communication from the pressure source (e.g. fluid pump 312)
to brake actuator 306, and flow of fluid between brake actuator 306
and fluid source, or reservoir, 310.
[0181] In some embodiments, valve 359 is a 3-port 3-way valve
having three ports and three positions. In some embodiments, a
first position 359a of valve 359 is a pressure buildup position, in
which pressure source 312 is in fluid communication with brake
actuator 306. In some embodiments, a second position 359b of valve
359 is a pressure maintenance position, in which there is no fluid
communication between pressure source 312 and brake actuator 306,
and fluid is prevented from flowing towards brake actuator 306 and
fluid source 310. In some embodiments, a third position 359c of
valve 359 is a pressure release position, in which brake actuator
306 is in fluid communication with fluid source 310, and fluid can
flow from the brake actuator to the reservoir.
[0182] In some embodiments, valve 359, and the transition thereof
between the three positions, is controlled by one or more
solenoids. In some embodiments, modulator-control-circuit(s) 356 is
connected to, or functionally associated with, the solenoid(s)
controlling operation of valve 359 to regulate its operation. In
some embodiments, valve 359 is a proportional valve.
[0183] The embodiment shown in FIG. 3C is similar to the embodiment
of FIG. 3A, having different normal orientations of the valves, and
additionally including pressure release valves and/or throttles. As
seen in FIG. 3C, brake modulator 352 includes two valves--a fluid
inlet valve 367 and a fluid release valve 368. Each of valves 367
and 368 has an open operative orientation and a closed operative
orientation. When in the open operative orientation, fluid inlet
valve 367 is adapted to provide hydraulic fluid to, and increase
the fluid pressure within, brake actuator 306. By contrast, fluid
release valve 368 is adapted to release fluid from, and to reduce
the fluid pressure within, brake actuator 306 when it is in the
open operative orientation.
[0184] In some embodiments, fluid inlet valve 367 is a 2-port 2-way
valve, having inlet and outlet ports, and two positions, as
described hereinabove with respect to fluid inlet valve 357 of FIG.
3A. In some embodiments, such as in the illustrated embodiment of
FIG. 3C, inlet valve 367 is normally open, as described hereinabove
with respect to FIG. 3A.
[0185] In some embodiments, fluid release valve 368 is a 2-port
2-way valve, having inlet and outlet ports, and two positions, as
described hereinabove with respect to fluid release valve 358 of
FIG. 3A. In the illustrated embodiment, fluid release valve 368 is
normally open.
[0186] As seen in FIG. 3C, in some embodiments, a pressure relief
valve 370 is disposed between fluid pump (i.e. pressure source) 312
and fluid inlet valve 367, to release any excess pressure provided
via the pump, prior to it being delivered to the brake actuator 306
via valve 367. Fluid delivered by pressure relief valve 370 is
returned to a fluid line down stream of reservoir 310 and upstream
of fluid pump 312, for future use. In the illustrated embodiment,
pressure relief valve 370 is normally open. However, in some
embodiments, pressure relief valve 370 may be normally closed.
[0187] In some embodiments, a pressure relief valve 372 is disposed
between brake actuator 306 and fluid release valve 368. Fluid
delivered by pressure relief valve 372 is returned to a fluid line
connecting reservoir 310, downstream of fluid release valve 368. In
the illustrated embodiment, pressure relief valve 372 is normally
closed. However, in some embodiments, pressure relief valve 372 may
be normally open.
[0188] In some embodiments, a throttle 374 may be disposed between
fluid inlet valve 367 and brake actuator 306, to further restrict
the flow rate of fluid from valve 367 to the brake actuator. In
some embodiments, a throttle 376 may be disposed between fluid
brake actuator 306 and fluid release valve 368, to further restrict
the flow rate of fluid from the brake actuator to the fluid release
valve.
[0189] In some embodiments, valves 367, 368, 370, and/or 372 may be
transitioned between the open operative orientation and the closed
operative orientation by solenoids. In some embodiments,
modulator-control-circuit(s) 356 is connected to, or functionally
associated with, the solenoids controlling operation of valves 367,
368, 370, and 372 and synchronizes their operation. In some
embodiments, valves 367, 368, 370 and/or 372 are proportional
valves.
[0190] As described hereinabove with respect to FIG. 2, in some
embodiments, a VCM including the VCM-based brake systems 336 of
FIGS. 3A to 3C may include a VCM controller 38, as shown in FIG. 1.
In some embodiments, wheel rotation profile inputs are received by
the VCM controller, which provides operational instruction inputs
to one or more of brake controller 302 and
modulator-control-circuit(s) 356.
[0191] According to some embodiments, an electrical power source
powering one or more of fluid pump 312,
modulator-control-circuit(s) 356, and brake controller 302, may be
mounted onto the vehicle platform, such as platform 12 of FIG. 1.
In some embodiments, the electrical power source of one or more of
pump 312, modulator-control-circuit(s) 356, and brake controller
302 may be disposed within the VCM, such as VCM 20 of FIGS. 1A and
1B. In some embodiments, one or more of pump 312,
modulator-control-circuit(s) 356, and brake controller 302 share a
common electrical power source.
[0192] It is a particular feature of embodiments of the disclosed
technology, which include a VCM-based brake control and VCM-based
ESC functionality, that the brake or ESC functionality can be added
to or removed from a wheel axle, without altering the vehicle
platform. For example, ESC functionality may be activated or
de-activated on specific track axles, may be operated when one
corner has some errors, or may be used to diagnose procedures that
require de-activation of some of the VCMs.
[0193] In some embodiments, the VCM, such as the VCM controller or
another circuit of the VCM, reports to a central controller of the
vehicle platform, such as control circuit(s) 116 (see FIGS. 1B and
2), a user interface, or an alert system of the vehicle, an
operational state of the brake functionality and/or of the ESC
functionality in each VCM.
[0194] In some embodiments of the disclosed technology, brake
and/or ESC functionalities may be provided by intercommunication
between VCMs of the vehicle. In some embodiments,
intercommunication between VCMs 20 occurs via VCM controllers 38
communicating with one another. In some embodiments,
intercommunication between VCMs 20 is via bus 119 (see FIG. 2),
which extends between the VCMs, via vehicle platform 12. In some
embodiments, intercommunication between VCMs 20 is via a VCM-VCM
bus (not explicitly shown), which is disconnected from vehicle
controller 116 on the vehicle platform.
[0195] In some embodiments, the communication between the VCMs
occurs without involving, or communicating with, vehicle controller
116 or another device disposed on the vehicle platform. In some
embodiments, vehicle platform 12 (FIGS. 1A, 1B, 2) is devoid of an
ESC system and/or of an ESC controlling unit.
[0196] In some embodiments, communication between the VCMs is
complemented by communication of one or more of the VCMs with an
external computing device (not explicitly shown). For example, in a
fully or partially autonomous vehicle, the VCMs may communicate
with an external controlling server.
[0197] In some embodiments, intercommunication between VCMs
includes intercommunication between brake controllers disposed in
different VCMs of the vehicle. Data exchange between the VCMs may
improve the ESC performance, for example by sharing among VCMs data
relating to the types of the VCMs, data relating to VCM subsystems
installed on each VCM, the status of such subsystems, historical
data relating to functionalities of each VCM, data relating to load
on each VCM, and the like. In some embodiments, brake modulators
352 are controlled solely by components of brake modules 350 at the
VCM(s), without receiving control signals from the vehicle
controller 116 or from another controller disposed on the vehicle
platform.
[0198] Communication between mounted VCMs may be between two VCMs
on the same side of the vehicle, whether by vertical division
(right VCMs, left VCMs) or by horizontal division (front VCMs, rear
VCMs). In some embodiments, all four VCMs may communicate with each
other.
Exemplary Method of Operating a Hydraulic VCM-Based Brake
System
[0199] Reference is now made to FIG. 4, which is a flowchart of a
method for operating a hydraulic VCM-based brake system, such as
VCM-based brake systems 236 and 336 of FIGS. 1B to 3C, according to
some embodiments of the disclosed technology.
[0200] As seen in FIG. 4, initially, a target wheel rotation rate
is obtained at step 402. In some embodiments, the target wheel
rotation rate is obtained by a VCM controller, such as controller
38 of FIG. 1B, or by a brake-control-circuit, such as
brake-control-circuits 202 or 302 of FIGS. 2 to 3C, disposed within
the VCM. In some embodiments, the target rotation rate is obtained
from another component of the vehicle, such as from a brake pedal
or button electrically associated with the VCM-based brake system,
or from a vehicle controller such as vehicle controller 116 (FIG.
2).
[0201] In some embodiments, the target rotation rate is lower than
a current rotation rate. In such embodiments, the target rotation
rate is intended to slow the speed of the vehicle, or to correct
vehicle yaw in accordance with instruction inputs received from an
ESC/ESP system. In some embodiments, the target rotation rate is
higher than a current rotation rate. In such embodiments, the
target rotation rate is intended to terminate a braking operation
and/or to cause acceleration of the vehicle.
[0202] At step 404, the actual, or current, wheel rotation rate is
compared to the obtained target rotation rate. In some embodiments,
the comparing is carried out by the VCM controller or by the
brake-control-circuit disposed within the VCM. In some embodiments,
the actual wheel rotation rate is measured by, or obtained from, a
rotation rate sensor, such as sensor 104 (FIG. 1B) disposed within
the VCM.
[0203] In some embodiments, as part of step 404, a pressure applied
by a brake actuator, such as brake actuator 206 or 306 (FIGS. 2 to
3C) is measured. In such embodiments, the comparison is between the
actual pressure applied by the brake actuator and a target pressure
to be applied by the brake actuator. In some embodiments, the
pressure applied by the brake actuator is pressure applied by the
actuator on a brake disc/drum.
[0204] When the comparison at step 404 reveals that the actual
wheel rotation rate is higher than the target wheel rotation rate,
VCM-based brake system carried out operations to reduce the actual
rotation rate, included in step block 410 which relates to
activation of a VCM-based brake actuator. When the comparison at
step 404 reveals that the actual wheel rotation rate is below the
target wheel rotation rate, VCM-based brake system carried out
operations to enable the increase of the actual rotation rate,
included in step block 420 which relates to deactivation of a
VCM-based brake actuator. When the comparison at step 404 reveals
that the actual wheel rotation rate is on target, VCM-based brake
system carried out operations to maintain the actual rotation rate,
included in step block 430.
[0205] As seen in FIG. 4, step block 410 relates to activation of
the VCM-based brake actuator, such as brake actuators 206 or 306
(FIGS. 2 to 3C). At step 412, a brake actuator pressure plan or
profile of the brake actuator is determined. For example, the
pressure plan may include a pressure plan within the actuator, the
duration of actuation, the pressure pulse rate, and the like. At
step 414 a fluid line between the brake actuator and a fluid
source, such as reservoir 210 or 310 (FIGS. 2 to 3C), and/or a
fluid pump, such as pump 212 or 312 (FIGS. 2 to 3C), is opened, or
is maintained open. In some embodiments, opening of the fluid line
is accomplished by controlling a fluid inlet valve or port disposed
between the brake actuator and the reservoir, such as valves 357,
359, or 367 (FIGS. 3A to 3C) to be in an open operative
orientation. As such, fluid pressure may be supplied from the fluid
source and/or the fluid pump to the brake actuator.
[0206] At step 416, a fluid line between the brake actuator and the
fluid source is closed, or is to kept closed. According to some
embodiments, closing of the fluid line is accomplished by closing a
release port, such as one of fluid release valves 358, 368 or a
position of valve 359 (FIGS. 3A to 3C), located along the fluid
line between the brake actuator and the fluid source, within the
VCM. In some embodiments, closing of the fluid line is accomplished
by setting a multi-states fluid release valve assembled within a
pressure modulator of the VCM to a closed state, so as to prevent
release of fluid pressure between the brake actuator and the fluid
source within the VCM.
[0207] At step 418, the VCM-based fluid pump, e.g. pump 212 or 312
(FIGS. 2 to 3C) is operated, or is maintained in operation, to
supply fluid pressure from the fluid source or reservoir toward the
brake actuator. In some embodiments, operation of the fluid pump is
regulated by a pump-control-circuit, which may form part of the
brake-control-circuit or of the VCM controller. The
pump-control-circuit may receive a target pressure, and may operate
or terminate operation of the pump to achieve that target
pressure.
[0208] It is appreciated that steps 412, 414, 416, and 418, within
the step block 410, may be carried in a different order than that
shown. For example, the opening of the fluid line at step 414 may
take place after the closing of the fluid line at step 416, and/or
after the operating of the fluid pump at step 418. As another
example, the closing of the fluid line at step 416 may occur before
the determining of the plan at step 412.
[0209] As mentioned above, step block 420 relates to deactivation
of the VCM-based brake actuator. At step 422 the pumping operation
of the VCM-based fluid pump is terminated, or, if the fluid pump
was previously inactive, it is maintained in an inactive state.
This prevents application of additional fluid pressure to the fluid
line connecting the fluid pump and the brake actuator.
[0210] At step 424, the fluid line between the fluid pump and/or
the fluid source within the VCM, and the brake actuator, is closed,
or is kept closed. In some embodiments, closing of the fluid line
is accomplished by controlling a fluid inlet valve or port located
along the fluid line between the fluid pump and/or the fluid source
and the brake actuator, such as valves 357, 359, or 367 (FIGS. 3A
to 3C), to be in the closed operative orientation. In some
embodiments, closing of the fluid line is accomplished by setting a
fluid inlet valve within a pressure modulator of the VCM to a
closed state, so as to close the fluid supply line and to prevent
an increase in fluid pressure between the fluid source and the
brake actuator.
[0211] At step 426, the fluid line between the brake actuator and
the fluid source is opened, or is maintained open, to reduce fluid
pressure in brake actuator. In some embodiments, opening of the
fluid line is accomplished by opening a release port, such as one
of fluid release valves 358, 368 or a position of valve 359,
located along the fluid line between the brake actuator and the
fluid source, within the VCM. In some embodiments, opening of the
fluid line is accomplished by setting the fluid release valve of a
pressure modulator of the VCM to an open state, such that the fluid
line is open to allow releasing of fluid pressure from the brake
actuator toward the fluid source.
[0212] It is appreciated that steps 422, 424, and 426, within the
step block 420, may be carried out in a different order than that
shown. For example, the closing at step 424 and/or the opening at
step 426 may occur prior to the terminating at step 422.
[0213] As mentioned above, step block 430 relates to maintaining
the operation of the VCM-based brake actuator. At step 432, the
pumping operation of the VCM-based fluid pump is terminated, or, if
the fluid pump was previously inactive, it is maintained in an
inactive state. This prevents application of additional fluid
pressure to the fluid line connecting the fluid pump and the brake
actuator.
[0214] At step 434, the fluid line between the fluid pump and/or
the fluid source within the VCM, and the brake actuator, is closed,
or is kept closed. In some embodiments, closing of the fluid line
is accomplished by controlling a fluid inlet valve or port located
along the fluid line between the fluid pump and/or the fluid source
and the brake actuator, such as valves 357, 359, or 367 (FIGS. 3A
to 3C), to be in the closed operative orientation. In some
embodiments, closing of the fluid line is accomplished by setting a
fluid inlet valve within a pressure modulator of the VCM to a
closed state, so as to close the fluid supply line and to prevent
an increase in fluid pressure between the fluid source and the
brake actuator.
[0215] At step 436, the fluid line between the brake actuator and
the fluid source is closed, or is kept closed. In some embodiments,
closing of the fluid line is accomplished by closing a release port
such as one of fluid release valves 358, 368 or a position of valve
359 (FIGS. 3A to 3C), located along the fluid line between the
brake actuator and the fluid source, within the VCM. In some
embodiments, closing of the fluid line is accomplished by setting a
multi-state fluid release valve assembled within a pressure
modulator of the VCM to a closed state, so as to prevent release of
fluid pressure between the brake actuator and the fluid source,
within the VCM.
[0216] It is appreciated that steps 432, 434, and 436, within the
step block 430, may be carried out in a different order than that
shown. For example, the closing at steps 434 and/or 436 may occur
prior to the terminating at step 432.
[0217] In some embodiments, one or more of the operations carried
out in steps of activating step block 410 (i.e. steps 412, 414,
416, and/or 418), de-activating step block 420 (i.e. steps 422,
424, and/or 426), and/or maintaining step block 430 (i.e. steps
432, 434, and/or 436) is regulated by the brake-control-circuit of
the VCM-based brake system, such as brake-control-circuit 202 or
302.
[0218] In some embodiments, following completion of any one of the
step blocks 410, 420, and/or 430, flow returns to step 404, to
repeat the comparison of the actual rotation rate and the target
rotation rate, for another iteration of the method of FIG. 4.
Fluid Pressure Controlled Hydraulic VCM-Based Brake System
[0219] Reference is now made to FIGS. 5A and 5B which are
mechanical and electrical schematic block diagrams of a VCM-based
brake system 536 functionally associated with, or including, a
VCM-based brake-modulator 550 and with a VCM-pressure-modulator
570, according to some embodiments of the disclosed technology.
Hydraulic VCM-based brake system 536, brake-modulator 550, and
pressure-modulator 570 are disposed within a VCM 20, similar to
that described hereinabove with respect to FIG. 1A. FIG. 5A
illustrates only the VCM-based brake system. However, it is
appreciated that the system illustrated in FIG. 5A would be
disposed within a VCM, as shown in FIGS. 1B and 2.
[0220] Hydraulic VCM-based brake system 536 may be an embodiment of
hydraulic VCM-based brake systems 336 described hereinabove with
respect to FIGS. 3A to 3C, and may include similar components,
subsystems, and functionalities.
[0221] As seen in FIG. 5A, hydraulic VCM-based brake system 536
includes a VCM-based brake-modulator 550, similar to the brake
modulator of FIGS. 3A to 3C, which is adapted to control operation
of brake actuator 506. In the illustrated embodiment, VCM-based
brake-modulator 550 is functionally associated with a
VCM-pressure-modulator 570 which functions as the brake-power
source, and is adapted to modulate the pressure of the braking
fluid supplied to the brake actuator 506.
[0222] As discussed hereinabove, hydraulic VCM-based brake system
536 is adapted to be disposed in a VCM 20 (FIG. 1A), which is
adapted to be mounted onto a vehicle platform 12 (FIG. 1A). The
vehicle platform is adapted to have multiple VCMs attached thereto.
As discussed herein, each VCM may include a dedicated VCM-based
brake system, which may be independent of the vehicle platform and
of the other VCMs. In some embodiments, each VCM-based brake system
includes, or is functionally associated with, a dedicated VCM-based
brake-modulator 550 as described herein. Typically, one or more of
the VCM-based brake-modulator 550 is adapted to receive control
inputs from a central controller, such as control circuit 116
(FIGS. 1B and 2) of the vehicle. In some embodiments, each
VCM-based brake-modulator 550 is additionally or alternatively
adapted to receive control inputs from a brake-control-circuit 502,
similar to brake-control-circuit 202 of FIG. 2.
[0223] In some embodiments, VCM-based brake-modulator 550 is
adapted to be integrated with, or form part of,
brake-control-circuit 502. Consequently, one or more
modulator-control-circuit(s) 556 of the brake-modulator may be
integrated within brake-control-circuit 502.
[0224] In some embodiments, VCM-pressure-modulator 570 includes a
fluid pump 512, which is adapted to generate fluid pressure for
actuating brake actuator 506. Fluid pump 512 is in fluid
communication with reservoir 510, and is associated with
accumulator 572, which forms part of the VCM-pressure-modulator 570
and is disposed downstream of pump 512. Pump 512 is adapted to
generate fluid at a target pressure, which pressurized fluid is
accumulated within accumulator 572. In some embodiments, a
no-return valve 574 forms part of VCM-pressure-modulator 570 and is
disposed on a fluid line connecting accumulator 572 with the
VCM-based brake-modulator 550, and ensures that fluid will only
flow from the accumulator toward the brake actuator, but not in the
opposite direction.
[0225] VCM-based brake-modulator 550 includes modulator valves,
adapted to be controlled by modulator-control-circuit 556. As seen
in FIG. 5A, VCM-based brake-modulator 550 includes two valves--a
fluid inlet valve 557 and a fluid release valve 558. However,
valves 557 and 558 may be replaced by a single 3-position valve,
substantially as described hereinabove with respect to FIG. 3B.
[0226] Each of valves 557 and 558 has an open operative orientation
and a closed operative orientation. When in the open operative
orientation, fluid inlet valve 557 is adapted to provide hydraulic
fluid to, and increase the fluid pressure within, brake actuator
506. By contrast, fluid release valve 558 is adapted to release
fluid from, and to reduce the fluid pressure within, brake actuator
506 when it is in the open operative orientation.
[0227] In some embodiments, fluid inlet valve 557 is a 2-port 2-way
valve, having inlet and outlet ports, and two positions. In some
embodiments, a first position 557a of inlet valve 557 is a pressure
buildup position, in which accumulator 572 is in fluid
communication with brake actuator 506, via no-return valve 574 and
inlet valve 557. In some embodiments, a second position 557b of
inlet valve 557 is a pressure maintenance position, in which there
is no fluid communication between the pressure source and brake
actuator 506, preventing fluid from flowing between brake actuator
506 and fluid source 510.
[0228] In some embodiments, such as in the illustrated embodiment
of FIG. 5A, inlet valve 557 is normally closed, such that it is
normally in the pressure maintenance position 557b.
[0229] In some embodiments, fluid release valve 558 is a 2-port
2-way valve, having inlet and outlet ports, and two positions. In
some embodiments, a first position 558a of fluid release valve 558
is a pressure maintenance position, in which there is no fluid
communication between the brake actuator 506 and the fluid source,
preventing fluid from flowing towards fluid source 510. In some
embodiments, a second position 558b of release valve 558 is a
pressure release position, in which brake actuator 506 is in fluid
communication with fluid source 510, and fluid can flow from the
brake actuator to the reservoir. In some embodiments, fluid release
valve 558 is normally closed, such that it is normally in the
pressure maintenance position 558a.
[0230] In some embodiments, valves 557 and 558 are transitioned
between the open operative orientation and the closed operative
orientation by solenoids. In some embodiments,
modulator-control-circuit(s) 556 is connected to, or functionally
associated with, the solenoids controlling operation of valves 557
and 558 and synchronizes their operation. In some embodiments,
valves 557 and 558 are proportional valves.
[0231] In some embodiments (not shown), no-return valve 574 forms
part of brake-modulator 550 and is disposed on a fluid line
connecting the VCM-based brake-modulator 550 with
VCM-pressure-modulator 570. In such embodiments, no-return valve
574 ensures that fluid will only flow from the
VCM-pressure-modulator 570 toward the brake actuator 506, but not
in the opposite direction.
[0232] As shown in FIG. 5B, and as described hereinabove with
respect to FIG. 2, in some embodiments, the brake controller 502
provides power and control inputs to VCM-based brake-modulator 550
and/or to VCM-pressure-modulator 570, as indicated by solid lines
in FIG. 5B, and may receive sensor readings from components of the
VCM-based brake modulator, as indicated by a dashed line in FIG.
5B. For example, the VCM-based brake modulator 550 may include a
brake-pressure-sensor 560 adapted to sense the pressure applied by
the brake actuator, such as by a brake caliper. As another example,
VCM-based brake to modulator 550 may include an
actuator-fluid-pressure-sensor adapted to sense the pressure of the
fluid provided to the brake actuator. As another example, VCM-based
brake modulator 550 may include a pressure-modulator-sensor 562
adapted to sense the pressure of the fluid supply provided to the
VCM-based brake modulator from VCM-pressure-modulator 570. Inputs
representing measurements or signals of the sensors 560 and/or 562
may be provided from the VCM-based brake modulator to brake
controller 502.
[0233] In some embodiments, the VCM including the VCM-based brake
systems 536 may further include a VCM controller, similar to the
VCM controller 38 shown in FIG. 1A. In some embodiments, the
VCM-based brake modulator and/or the VCM-pressure-modulator may be
controlled by the VCM controller.
[0234] According to some embodiments, an electrical power source
powering one or more of VCM-pressure modulator 570, and
specifically pump 512, components of VCM-based brake modulator 550,
brake controller 502, and/or VCM controller 538 may be mounted onto
the vehicle platform, such as platform 12 of FIG. 1. In some
embodiments, the electrical power source may be disposed within the
VCM, such as VCM 20 of FIGS. 1A and 1B. In some embodiments, one or
more of VCM-pressure modulator 570, and specifically pump 512,
components of VCM-based brake modulator 550, brake controller 502,
and/or VCM controller 538 may share a common electrical power
source.
[0235] In some embodiments, the VCM, such as VCM controller 538 or
another circuit of the VCM, reports to a central controller of the
vehicle platform, such as control circuit(s) 116 (see FIGS. 1B and
2), a user interface, or an alert system of the vehicle, an
operational state of VCM-pressure modulator 570 and/or of VCM-based
brake modulator 550.
[0236] As discussed hereinabove with respect to FIGS. 3A to 3C,
also in the embodiment of FIGS. 5A and 5B, the VCMs may communicate
with one another, wirelessly, via a bus, which may be mounted on
the vehicle platform or external thereto, or via an external
computing device such as a cloud based computer.
Exemplary Method of Operating a Hydraulic VCM-Based Brake System
with an Accumulator
[0237] Reference is now made to FIGS. 6A and 6B, which together are
a flowchart of a method for operating a hydraulic VCM-based brake
system including or associated with a VCM-pressure modulator and/or
a VCM-based brake modulator, such as VCM-based brake system 536 of
FIGS. 5A and 5B, according to some embodiments of the disclosed
technology.
[0238] As seen in FIG. 6A, initially at step 600, pressure is built
up in an accumulator disposed downstream a fluid pressure pump,
such as accumulator 572 (FIG. 5A), by operation of the
VCM-pressure-modulator activating a fluid pump thereof, such as
(fluid pump 512). The pressurized fluid in accumulator 572 is
stored for future use, as explained hereinbelow.
[0239] A target fluid pressure required in the fluid supply line
upstream of the brake actuator, such as brake actuator 506 (FIG.
5A) is obtained at step 602. In some embodiments, the target fluid
pressure is obtained by a VCM controller, such as controller 538
(FIG. 5B), or by a brake-control-circuit, such as
brake-control-circuits 502 (FIG. 5A), disposed within the VCM. In
some embodiments, the target fluid pressure is obtained from
another component of the vehicle, such as from a brake pedal or
button electrically associated with the VCM-based brake system, or
from a vehicle controller such as vehicle controller 116 (FIG. 2).
In some embodiments, target fluid pressure is calculated or
determined using callout tables based on a brake performance
profile required by the brake actuator.
[0240] At step 604, the actual, or current, brake fluid pressure is
compared to the obtained target pressure. In some embodiments, the
comparing is carried out by the VCM controller or by the
brake-control-circuit disposed within the VCM. In some embodiments,
the actual pressure is measured by, or obtained from, a fluid
pressure sensor, such as an actuator-fluid-pressure-sensor disposed
upstream of the brake actuator. In some embodiments, the actual
pressure is determined in accordance to measurements of the
pressure applied by the actuator on a brake disc/drum.
[0241] When the comparison at step 604 reveals that the actual
brake fluid pressure is higher than the target brake pressure,
VCM-based brake system carried out operations to reduce the actual
brake fluid pressure, included in step block 620 which relates to
de-activation of a VCM-based brake actuator. When the comparison at
step 604 reveals that the actual fluid brake pressure is below the
target brake fluid pressure, VCM-based brake system carried out
operations to increase the actual brake fluid pressure, included in
step block 610 (FIG. 6B) which relates to activation of a VCM-based
brake actuator. When the comparison at step 604 reveals that the
actual brake pressure is on target, VCM-based brake system carried
out operations to maintain the actual brake fluid pressure,
included in step block 630.
[0242] As seen in FIG. 6B, step block 610 relates to activation of
the VCM-based brake actuator, such as brake actuator 506 (FIG. 5A).
At step 612, a brake fluid actuator pressure plan or profile of the
brake actuator is determined. For example, the pressure plan may
include a pressure plan within the actuator, the duration of
actuation, a pressure pulse rate, and the like. At step 614 a fluid
line between the brake actuator and a pressurized fluid source,
such as accumulator 572 (FIG. 5A), and/or a fluid pump, such as
pump 512 (FIG. 5A), is opened, or is maintained open. In some
embodiments, opening of the fluid line is accomplished by
controlling a fluid inlet valve disposed between the brake actuator
and the reservoir, such as valves 557 (FIG. 5A) to be in an open
operative orientation. As such, fluid pressure may be supplied from
the accumulator to the brake actuator, without requiring
pressurizing of the fluid when the braking command is received or
the need for braking is identified. Having a pressurized fluid
available may improve performance over systems requiring operating
a fluid pump as pressurize fluid is required. Not requiring the
activation of the pump may also result in a quieter brake system
and increased durability of mechanical parts.
[0243] At step 616, a fluid line between the brake actuator and a
fluid source, such as reservoir 510 (FIG. 5A) is closed, or is kept
closed. According to some embodiments, closing of the fluid line is
accomplished by closing a release port, such as one of fluid
release valve 558 (FIG. 5A), located along the fluid line between
the brake actuator and the fluid source, within the VCM. In some
embodiments, closing of the fluid line is accomplished by setting
the fluid release valve within a pressure modulator of the VCM to a
closed state, so as to prevent release of fluid pressure between
the brake actuator and the fluid source within the VCM.
[0244] At step 617, the actual, or current, pressure within the
accumulator is compared to the target fluid pressure. In some
embodiments, the comparing is carried out by the VCM controller or
by the brake-control-circuit disposed within the VCM. In some
embodiments, the actual pressure within the accumulator is measured
by, or obtained from, a pressure sensor, such as
pressure-modulator-sensor 562 (FIG. 5B) disposed within the
VCM.
[0245] If the actual pressure within the accumulator is below the
target fluid pressure, at step 618, the VCM-based fluid pump, such
as pump 512 (FIG. 5A) is operated, or is maintained in operation,
to supply pressurized fluid to the accumulator within the
VCM-pressure modulator 570. In some embodiments, operation of the
fluid pump is regulated by a pump-control-circuit, which may form
part of the brake-control-circuit or of the VCM controller. The
pump-control-circuit may receive a target pressure, and may operate
or terminate operation of the pump to achieve that target
pressure.
[0246] If the actual pressure within the accumulator is above, or
on, the target pressure, at step 619, the pumping operation of the
VCM-based fluid pump is terminated, or, if the fluid pump was
previously inactive, it is maintained in an inactive state. This
prevents increasing of the fluid pressure within the
accumulator.
[0247] Once the steps in step block 610 have been completed, the
flow may return to step 604 to repeat the comparison of the actual
brake pressure and the target brake pressure, for another iteration
of the method of FIGS. 6A and 6B.
[0248] It is appreciated that steps 612, 614, 616, and 617 within
the step block 610, may be carried in a different order than that
shown. For example, step 617 may occur right after step 612. As
another example, step 616 may occur prior to step 614.
[0249] Returning to FIG. 6A, as mentioned above, step block 620
relates to deactivation of the VCM-based brake actuator. At step
622 the pumping operation of the VCM-based fluid pump is
terminated, or, if the fluid pump was previously inactive, it is
maintained in an inactive state. This prevents additional fluid
pressure buildup within the accumulator, and application of
pressurized fluid to the fluid line connecting the accumulator and
the brake actuator.
[0250] At step 624, the fluid line between the accumulator within
the VCM, and the brake actuator, is closed, or is kept closed. In
some embodiments, closing of the fluid line is accomplished by
controlling a fluid inlet valve or port located along the fluid
line between the accumulator and the brake actuator, such as valve
557 (FIG. 5A), to be in the closed operative orientation.
[0251] At step 626, the fluid line between the brake actuator and
the fluid source is opened, or is maintained open, to reduce fluid
pressure in brake actuator. In some embodiments, opening of the
fluid line is accomplished by opening a release port, such as fluid
release valve 558, located along the fluid line between the brake
actuator and the fluid source, within the VCM.
[0252] It is appreciated that steps 622, 624, and 626, within the
step block 620, may be carried out in a different order than that
shown. For example, the closing at step 624 and/or the opening at
step 626 may occur prior to the terminating at step 622. Following
completion of the steps in step block 620, the flow may return to
step 604 to repeat the comparison of the actual brake pressure and
the target brake pressure, for another iteration of the method of
FIG. 6.
[0253] As mentioned above, step block 630 relates to maintaining
the operation of the VCM-based brake actuator. At step 633, the
fluid line between the brake actuator and the fluid source is
closed, or is kept closed. In some embodiments, closing of the
fluid line is accomplished by closing a release port such as fluid
release valve 558 (FIG. 5A), located along the fluid line between
the brake actuator and the fluid source, within the VCM.
[0254] At step 634, the fluid line between the accumulator and the
brake actuator, is closed, or is kept closed. In some embodiments,
closing of the fluid line is accomplished by controlling a fluid
inlet valve or port located along the fluid line between the
accumulator and the brake actuator, such as valve 557 (FIG. 5A), to
be in the closed operative orientation.
[0255] The flow then may continue to step 617, in which the actual,
or current, pressure within the accumulator is compared to the
fluid target pressure, as described hereinabove.
[0256] If the actual pressure is below the target pressure, the
flow continues to step 618, as described hereinabove. If the actual
pressure is on target, the activation step block 630 is
terminated.
[0257] Following completion or termination of the steps in step
block 630, the flow may return to step 604 to repeat the comparison
of the actual brake pressure and the target brake pressure, for
another iteration of the method of FIG. 6.
[0258] In some embodiments, one or more of the operations carried
out in steps of activating step block 610 (i.e. steps 612, 614,
616, 617, and/or 618), de-activating step block 620 (i.e. steps
622, 624, and/or 626), and/or maintaining step block 630 (i.e.
steps 433, 434, and/or 437) is regulated by the
brake-control-circuit of the VCM-based brake system, such as
brake-control-circuit 502.
[0259] It is a particular feature of the VCM-based brake system of
FIGS. 5A and 5B, and of the corresponding method of FIG. 6, that
the pump 512 causes fluid in a target pressure to be accumulated in
accumulator 572. As such, when a braking command is received, the
fluid is already pressurized and ready for the brake actuator to
apply the required pressure, as soon as the suitable valves open.
By contrast, in the prior art, as well as in the embodiment of
FIGS. 2 to 3C, the pump only initiates pressurizing of the fluid
when the braking command is received, which may lead to a slower
response time than in the embodiment of FIG. 5.
VMC-Based Brake System with Brake Regeneration
[0260] Reference is now made to FIGS. 7A and 7B, which are
schematic block diagrams of VCM-based brake systems 736a and 736b
having brake regeneration according to some embodiments of the
disclosed technology.
[0261] VCM-based brake systems 736a (FIG. 7A) and 736b (FIG. 7B)
may be embodiments of VCM-based brake systems 36 and 236 of FIGS.
1B and 2, respectively, and are adapted to be accommodated within a
VCM 20, between a vehicle platform 12 and a wheel 28 (see FIGS. 1B
and 2) assembled to VCM 20.
[0262] VCM-based brake systems 736a and 736b each include a
brake-control-circuit (e.g. one or more brake controller) 702,
substantially as described hereinabove with respect to
brake-control-circuits 102 and 202 of FIGS. 1B and 2. In some
embodiments, the VCM-based brake systems further include a rotation
rate sensor 704, adapted to report to the brake-control-circuit a
rotation rate of a wheel attached to the VCM.
[0263] Each of VCM-based brake systems 736a and 736b includes a
brake actuator (e.g. a brake caliper) 706, adapted to regulate the
rotation rate of the wheel, based on actuation inputs received from
brake-control-circuit 702 substantially as described hereinabove
with respect to brake actuators 106 and 206 of FIGS. 1B and 2.
[0264] As described hereinabove with respect to FIG. 1B, VCM-based
brake systems 736 may further include one or more brake power
sources, disposed within VCM 20. The brake power source(s) is
adapted to provide operational power to brake actuator 706 and/or
to brake-control-circuit 702.
[0265] According to some embodiments, VCM-based brake systems 736
include one or more brake-interface-circuits 708 adapted to provide
an interface between brake-control-circuit 702 and one or more
vehicle control circuits mounted outside VCM 20, substantially as
described hereinabove with respect to FIG. 1B. For example,
brake-interface-circuit 708 may provide an interface with a general
vehicle controller 116 mounted onto vehicle platform 12, which is
functionally associated with, or includes, a processor 117. In some
embodiments, brake-interface-circuit 708 form part of vehicle
connection interface 24 (FIG. 1A). In some embodiments,
brake-interface-circuit 708 is adapted to connect to a platform
connector 118, which may form part of VCM-connection interface 14
(FIG. 1A) mounted onto vehicle platform 12. In some embodiments,
brake-interface-circuit 708 includes one or more transmitters to
establish wireless connection with circuits outside VCM 20, such as
with a general vehicle controller mounted onto the vehicle
platform.
[0266] According to some embodiments, vehicle platform 12 includes
a plurality of platform connectors 118. In some embodiments, two or
more of platform connectors 118 are interconnected by a
platform-VCM bus 119. In some embodiments, platform-VCM bus 119 is
used for communication between computing circuits assembled within
multiple VCMs 20.
[0267] VCM-based brake systems 736b, shown in FIG. 7B, is a
hydraulic brake system. As such, VCM-based brake systems 736b
further includes a hydraulic fluid source 710, and a hydraulic
fluid pump 712, substantially as described hereinabove with respect
to FIG. 2.
[0268] VCM-based brake systems 736a and 736b each include a brake
regeneration module 740. In some embodiments, brake regeneration
module 740 is associated with a motor coupled to a wheel hub
forming part of VCM 20, onto which the wheel is mounted. In some
embodiments, brake regeneration module 740 may include a motor
inverter connected to the motor. In some embodiments, brake
regeneration module 740 may includes a motor control circuit
connected to the motor inverter. In some embodiments, brake
regeneration module 740 is adapted to regulate the kinematic
behavior of the wheel by receiving operational signals to apply
brake regeneration prior to operating brake actuator 706. The
operational signals may be received at the motor inverter of the
brake regeneration module.
[0269] In some embodiments, such as the embodiment of FIG. 7A,
brake actuator 706 is electrical, and is powered by electrical
power source. In some embodiments, the electrical power source is
disposed within the VCM, which may enable the use of simpler power
sources (e.g. batteries, capacitors) per VCM-based brake system
than when using a central power source. Localized power sources may
also improve a power performance profile of the vehicle and/or VCM,
and may enable local charging of the VCM and a longer duration
between charges. Use of local power sources may also reduce the
complexity, capacity requirements, size, weight, cost, and/or
production complexity of the power source(s) or power system
mounted onto the vehicle platform.
[0270] In some embodiments, VCM-based brake systems 736a and 736b
are adapted to regenerate the power sources. In some embodiments,
the VCM-based brake systems regenerates power sources disposed
within the VCM. In some embodiments, the VCM-based brake systems
regenerate one or more power source(s) mounted onto the vehicle
platform.
Exemplary Methods of Operating a VCM-Based Brake System with Brake
Regeneration
[0271] Reference is now made to FIGS. 8A and 8B, which are
flowcharts of methods for operating a VCM-based brake system having
brake regeneration functionality, according to some embodiments of
the disclosed technology. The methods of FIGS. 8A and 8B may be
implemented, for example, by such as VCM-based brake systems 736a
and 736b of FIGS. 7A and 7B.
[0272] As seen in FIG. 8A, at an initial step 802, a target wheel
rotation rate is received, for example as described hereinabove
with respect to step 402 of FIG. 4. In some embodiments, the target
rotation rate is lower than a current rotation rate. In such
embodiments, the target rotation rate is intended to slow the speed
of the vehicle, or to correct vehicle yaw in accordance with
instruction inputs received from an ESC/ESP system. In some
embodiments, the target rotation rate is higher than a current
rotation rate. In such embodiments, the target rotation rate is
intended to terminate a braking operation and/or to cause
acceleration of the vehicle.
[0273] At step 804, the actual, or current, wheel rotation rate is
compared to the obtained target rotation rate. In some embodiments,
the comparing is carried out by the VCM controller or by the
brake-control-circuit disposed within the VCM. In some embodiments,
the actual wheel rotation rate is measured by, or obtained from, a
rotation rate sensor, such as sensor 704, (FIG. 7A) disposed within
the VCM.
[0274] When the comparison at step 804 reveals that the actual
wheel rotation rate is below than the target wheel rotation rate,
at step 808 VCM-based brake system carries out operations to
increase the actual rotation rate, for example by deactivation of
the VCM-based brake actuator (e.g. actuator 706 of FIGS. 7A and
7B). In some embodiments, the operations carried out at step 808
may be similar or equivalent to operations carried out in step
block 420 of FIG. 4.
[0275] When the comparison at step 804 reveals that the actual
wheel rotation rate is on target, at step 810 VCM-based brake
system carries out operations to maintain the current brake
actuation. In some embodiments, the operations carried out at step
810 may be similar or equivalent to operations carried out in step
block 430 of FIG. 4.
[0276] When the comparison at step 804 reveals that the actual
wheel rotation rate is higher than the target rotation rate,
VCM-based brake system carries out operations to reduce the actual
rotation rate. In some embodiments, reducing the actual rotation
rate is by activating a brake regeneration module (module 740,
FIGS. 7A and 7B) at step 806. The activated brake regeneration
functionality is applied to a wheel motor, and results in reduction
of the rotation rate of the wheel.
[0277] At step 812, following activation of the brake regeneration
module, the actual wheel rotation rate is compared to the target
regeneration rate once again. When the comparison at step 812
reveals that the actual rotation rate is below the target rotation
rate, the flow continues to step 808, as discussed hereinabove.
When the comparison at step 812 reveals that the actual rotation
rate is on target, the flow continues to step 810, as discussed
hereinabove. When the comparison at step 812 reveals that the
actual rotation rate is still higher than the target rotation rate,
the actual rotation rate may be further reduced is by activating
the VCM-based brake actuator, at step 814. In some embodiments, the
operations carried out at step 814 may be similar or equivalent to
operations carried out in step block 410 of FIG. 4.
[0278] In some embodiments, step 804 is accomplished by comparing
an actual pressure applied by a brake actuator to a target
pressure, as described hereinabove with respect to FIG. 6.
[0279] In some embodiments, following completion of steps 808, 810,
and/or 814, the flow returns to step 804 for comparison of the
updated actual wheel rotation rate to the target rotation rate, and
for another iteration of the method.
[0280] In some embodiments, operation of the VCM-based brake system
may be defined in accordance with a VCM-plan. In some embodiments,
the VCM-plan may define the operation of the brake regeneration
module 740 (FIGS. 7A and 7B). For example, when the plan is active
(e.g. purchased, payed for, and/or activated per vehicle type), the
brake regeneration functionality can be used in conjunction with
brake actuator. FIG. 8B illustrates a method similar to that of
FIG. 8A, but differing therefrom in the existence of a plan for
activation of brake regeneration, such that the brake regeneration
functionality is only activated if the plan is active.
[0281] FIG. 8B initiates with steps 802 and 804, as described
hereinabove with respect to FIG. 8A. Following the comparison at
step 804, if the actual rotation rate is determined to be on target
the flow continues to step 810, and if the actual rotation rate is
determined to be below the target rotation rate, the flow continues
to step 808, both as described hereinabove with respect to FIG.
8A.
[0282] Unlike the method of FIG. 8A, in FIG. 8B, when the
comparison at step 804 indicates that the actual rotation rate is
higher than the target rotation rate, at step 820 the VCM-based
brake system evaluates whether it includes a brake regeneration
plan, or if such a plan is active. If at step 820 it is determined
that the VCM-based brake system includes a (active) brake
regeneration plan, the flow continues to step 806, substantially as
described hereinabove with respect to FIG. 8A. Otherwise, if no
brake regeneration plan is included, or if such a plan is not
active, the flow continues to step 814 for activation of the brake
actuator, substantially as described hereinabove.
[0283] In some embodiments, the evaluation at step 820 is performed
by a computing unit included in the VCM, such as the
brake-control-circuit or the VCM controller. In some embodiments,
the evaluation at step 820 is performed by a computing unit located
on the vehicle platform, such as controller 116. In some
embodiments, the evaluation at step 820 is performed by
communication with a remote computer (e.g. a cloud based
server).
[0284] The method of FIGS. 8A and 8B, relating to brake
regeneration, are particularly useful in VCMs which include, in
addition to the VCM-based brake system, a powertrain subsystem. In
some embodiments, the VCM includes, in addition to the VCM-based
brake system, also a steering system, such as steering system 32 of
FIG. 1B. In some such embodiments, at step 812, if the actual
rotation rate is still higher than the desired rotation rate, the
steering system may be used to further reduce the rotation rate,
for example by causing two opposing wheels to turn toward each
other. Braking by steering may be used in conjunction with brake
regeneration, or in a VCM which does not have a brake regeneration
functionality.
[0285] In some embodiments, a VCM-based brake system plan is
selected after connecting the VCM to the vehicle platform, for
example by plug and play of the VCM. In some embodiments, the
VCM-based brake system plan is selected in accordance with an
insurance plan. In some embodiments, the VCM-based brake system
plan is selected in accordance with a VCM service plan, where the
VCM is provided as a service. In some embodiments, the VCM-based
brake system plan is selected in accordance with a model of the
vehicle. In some embodiments, the VCM-based brake system plan is
selected in accordance with a type of the VCM, such as rear/front
VCM, or motorized/not-motorized VCM. In some embodiments, the
VCM-based brake system plan is selected in accordance with a
preference of the driver or operator of the vehicle. In some
embodiments, the VCM-based brake system plan is selected or
terminated when the VCM is in diagnostic/test state, whether
attached to or detached from the vehicle platform.
[0286] The vehicle platforms and VCMs discussed hereinabove form
part of a vehicle. The vehicle may be for example, a private
vehicle, a passenger car, a commercial vehicle, an autonomous,
human driven, or remote controlled vehicle, a 4-wheeled car, a
truck, a bus, and/or a trailer. In some vehicles, each VCM includes
a VCM-based brake system.
[0287] In some vehicles, as shown for example in FIG. 7A, a front
VCM and a rear VCM may have different types of VCM-based brake
systems, which may differ in one or more of: a type of or structure
brake actuator, a type or structure of brake-control-circuit, and
operational profile defined for the brake system. In some vehicles,
the front VCM and the rear VCM have different types of VCM-based
brake systems, which may differ in one or more of: being hydraulic
or non-hydraulic, a type of structure of brake actuator, a type or
structure of brake controller, and/or an operational profile.
[0288] According to some embodiments, the type of a VCM-based brake
system is defined by one or more characteristics. The
characteristics may include, for example:
[0289] (1) Location of the VCM on the vehicle platform (e.g.
front/rear corner/right side/left side);
[0290] (2) Brake actuator mechanism (e.g. mechanical, hydraulic,
electrical, having a designated quality specifications);
[0291] (3) Brake actuator operational/performance profile (e.g.
size, area of contact, response time);
[0292] (4) Brake controller feature(s) (e.g. operational functions,
number of outputs, available inputs);
[0293] (5) Power source of one or more of the brake actuators and
the brake-control-circuit; and
[0294] (6) Mechanical/electrical interface for connection to the
vehicle platform.
[0295] As mentioned hereinabove, in some embodiments, the braking
functionality of vehicle speed reduction brake, for example by
driver operated brake, is provided by activating the brake actuator
without using a brake pedal.
GENERAL
[0296] It is expected that during the life of a patent maturing
from this application many relevant brake actuators and
brake-control-circuits will be developed. The scope of the terms
brake actuators and brake-control-circuits are intended to include
all such new technologies a priori.
[0297] It is appreciated that certain features of the invention,
which are, for clarity, described in the context of separate
embodiments, may also be provided in combination in a single
embodiment. Conversely, various features of the invention, which
are, for brevity, described in the context of a single embodiment,
may also be provided separately or in any suitable subcombination
or as suitable in any other described embodiment of the invention.
Certain features described in the context of various embodiments
are not to be considered essential features of those embodiments,
unless the embodiment is inoperative without those elements.
Although the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications and variations will be apparent to those skilled in
the art. Accordingly, it is intended to embrace all such
alternatives, modifications and variations that fall within the
spirit and broad scope of the appended claims.
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